The Supreme Court has been asked to decide whether a state can deny to widowers the workmen's compensation death benefits it grants to widows.

The issue is raised by a 5-to-1 ruling by the Missouri Supreme Court that dissimilar treatment of workers and spouses in work-related accidents solely on the basis of sex doesn't deny the equal protection of the laws guaranteed by the Constitution.

The case involves a 1925 Missouri workmen's compensation law based on a concept widely held in that era: the death of a spouse raises more urgent problems for a woman than a man, particularly because a woman has a more difficult time finding a job at a wage comparable to a man's.

Typically, the Missouri law implemented the concept by providing full benefits to a widow on the automatic assumption that she had been totally dependent for support upon her husband's wages. By contrast, the law said that a widower, unless mentally or physically incapacitated, is entitled to benefits only if he proves he had been dependent for support upon his wife's wages.

In 1977, Ruth Wengler, a drugstore clerk in Fredericktown, Mo., was killed when struck by a car on her employer's parking lot. Her husband, Paul, a liquor store owner, sought but was denied death benefits of an estimated $30,000 to $40,000. He had died in a work-related accident, the state would have paid benefits to Ruth routinely.

Turned down by the state, Wengler sued. He stipulated that he had not been dependent for support upon his wife's wages, even in part. He also stipulated that neither a physical nor a mental impairment prevented him from earning a living.

Last June, in the opinion for the Missouri Supreme Court majority, Judge John E. Bardgett emphasized that no claim had been made that there was "no important governmental objective to be served" when the 1920s legislature made the conclusive presumption that a working spouse's death inflicted a "more immediate and pronounced" economic hardship on women than men.

But the dissenting judge, Robert E. Seiler, said the law unconstitutionally discriminates against the married woman who contributes to family income without the guarantee, enjoyed by her husband, that the family won't lose her contribution if she dies in a job-related accident.

Seiler also cited decisions in which the U.S. Supreme Court, starting in 1975, condemned legislation that, on the basis of what the court termed "archaic and overbroad generalizations," results in "casting female wage-earners in a light which denigrates their economic contributions to their families' support."

Two days before the Missouri Supreme Court ruled against Wengler, the U.S. Supreme Court reiterated its position in a unanimous ruling against sex distinctions in the context of public assistance for unemployed parents.

Laws that reflect the "baggage of sexual stereotypes" in classifying by sex must fall, the justices said. Three weeks later, however, the Missouri tribunal denied Wengler's request for a rehearing.

In most states, workmen's compensation laws presume that surviving spouse, whether widow or widower, had been dependent on the mate's wages.In three states where there was a contrary presumption similar to Missouri's, the highest state tribunal in each, relying on the U.S. Supreme Court rulings, invalidated discriminatory proof-of-dependency requirements.

"Only Missouri continues to march to a different time, "Wengler's lawyer, John W. Reid II, said in his petition for Supreme Court review.