The Supreme Court ruled yesterday that civil rights lawyers can be required to give up the right to seek reimbursement of their legal fees as a condition of favorable settlements for their clients.

Three dissenting justices and a wide array of civil rights groups said the decision would make it more difficult for the poor, blacks, women, the disabled and others covered by various civil rights laws to obtain legal help.

The case, Evans v. Jeff D., involved a lawyer for the Idaho Legal Aid Society, L. Charles Johnson, who sued the state in 1980 on behalf of about 2,000 emotionally and mentally ill children, claiming that state institutions did not provide them with adequate education or health care.

In 1983, one week before the trial, the state offered Johnson almost everything he had sought, so long as he gave up his right under federal law to seek to have the state pay his legal fees.

Johnson, who said his legal fees amounted to about $50,000, accepted the offer subject to court approval, concluding that he was ethically required to take the best deal he could get for his clients. The 9th U.S. Circuit Court of Appeals later threw out the fee waiver.

In reversing the Circuit Court's decision yesterday, Justice John Paul Stevens said barring fee waiver agreements "would itself impede vindication of civil rights" by making defendants in civil rights cases -- particularly those involving large legal fees -- less willing to settle.

He dismissed in a footnote as "premature" and "as a practical matter . . . remote" the threat that the ruling would shrink the pool of lawyers willing to take such cases.

In a dissent, Justice William J. Brennan Jr., joined by Justices Thurgood Marshall and Harry A. Blackmun, criticized the majority for frustrating Congress' intent to help ensure the availability of lawyers in civil rights cases. He said it was "embarrassingly obvious" that "permitting fee waivers will seriously impair the ability of civil rights plaintiffs to obtain legal assistance."

The justices, setting the stage for a ruling next term on the rights of victims of AIDS (acquired immune deficiency syndrome), also agreed yesterday to decide whether federal law prohibits recipients of federal aid from discriminating against people with contagious diseases.

The case the court accepted, School Board of Nassau County, Fla. v. Gene H. Arline, asks whether a teacher could be dismissed because of her chronic susceptibility to infectious tuberculosis.

The teacher sued, saying that her dismissal violated the Rehabilitation Act of 1973, which forbids discrimination against the handicapped. Arline argued, and the 11th U.S. Circuit Court of Appeals in Atlanta agreed last year, that tuberculosis was a "handicap" covered by the act.

The appeals court said Congress excluded certain afflictions, such as alcoholism and drug abuse, from coverage under the act but did not exclude contagious diseases.

While the case does not involve AIDS, school board officials argued in their appeal to the high court that the "far-reaching" appeals court ruling would protect AIDS victims from dismissal from their jobs and other actions.

In other cases yesterday, the court upheld an Iowa rule that severely limits television and radio advertising by lawyers, prohibiting spots that use "dramatic voices" or "self-laudatory statements." A Des Moines television station pulled three ads by a local law firm that involved dramatizations after complaints by the state bar's ethics committee.

The Iowa Supreme Court said that action was justified by the threat of lawyers using television for "crass personal promotion" and manipulating uninformed viewers who would be tempted to "grab the phone and make a call" after seeing such ads.

The court yesterday refused to find that the Iowa rule violates the First Amendment, dismissing the case "for want of a substantial federal question." Justices Byron White, Blackmun and Stevens said they would have heard arguments in Humphrey v. Committee on Professional Ethics.

The court also agreed to decide:

*Whether the town of Newton, N.H., can enforce an arrested man's promise not to sue police officers or other officials for violating his constitutional rights in exchange for the prosecutor's agreement to drop the charges against him. The 1st U.S. Circuit Court of Appeals invalidated a release form signed by a man arrested for witness-tampering on grounds that such promises are against public policy. The case is Newton v. Rumery.

*Whether the U.S. government may require that three Canadian films on acid rain and nuclear war be labeled "political propaganda." A federal appeals court in California, ruling in Meese v. Keene, said the government's practice of labeling foreign films under the Foreign Agents Registration Act violated the First Amendment. A case involving the films is pending here before the U.S. Court of Appeals.

*Whether Missouri may deny unemployment benefits to pregnant women who quit and cannot get their jobs back once they decide to return to work. The Missouri Supreme Court, ruling in Wimberly v. Labor and Industrial Relations Commission, said the denial did not violate federal law.

The justices also declined to upset the conviction of U.S. District Court Judge Harry E. Claiborne, the first sitting federal judge ordered to prison. Claiborne, who has remained free pending appeal of his 1984 conviction for filing false tax reports, faces a two-year prison sentence and a possible move to have him impeached.