D.C. Superior Court Judge Robert A. Shuker dismissed yesterday, a student's complaint that she was dismissed from George Washington University Medical School because of her race, sex and physical appearance.

In a 14 1/2-page opinion, Shuker ruled that the dismissal of Lillie Walker, 35, of 1121 24th Street NW, was legal because the university did not act in an "arbitrary, capricious, malicious of discriminatory" manner.

Walker charged in a suit filed last "May that her dismissal from the medical school was based on her performance in an 18-day job as an intern at the Psychiatric Institute in Rockville last November. She had asked the court to force the medical school to award her a degree plus compensatory damages and costs.

Most of the testimony in a week long trial in july centered on the internship although the court's decision noted that Walker's entire academic career was reviewed by an educational evaluation committee at the university. Walker, who was notified of her dismissal May 11, was scheduled for graduation May 27.

In addition to the internship, Walker had failed a pharmacology course and a course in primary care. She repeated and passed the courses at other schools but was warned prior to taking the internship that any further failures would lead to dismissal from George Washington.

The three courses Walker failed totaled 23 semester hours of credit, and medical school regulations call for a hearing and possible dismissal if a student fails 20 semester hours.

Dr. Norman Karl, Walker's supervisor at Rockville, testified in court that Walker missed 10 to 12 meetings with staff members in the 18-day internship period, including a final meeting she specifically had been asked to attend.

Walker, who testified that she is $26,000 in debt because of her studies, has been accepted to a residency at the State University of New York. That probably will be cancelled because she does not have a medical degree.

Neither Walker nor her attorneys, all of whom are out of town, could be reached yesterday for comment.