SEMINAL FLUID COMPONENTS COLLECTED FROM 300 POSTMENARCHEAL WOMEN EXAMINED AT PARKLAND MEMORIAL HOSPITAL, DALLAS, TEX., AFTER AN ALLEGED SEXUAL ASSAULT WAS ANALYZED TO ASCERTAIN THE RELATIVE VALUE OF ACID PHOSPHATASE DETERMINATION AND SPERMATOZOAL DETECTION IN FRESH UNSTAINED AND IN FIXED STAINED SPECIMENS OF VAGINAL FLUID. IN THE MAJORITY OF CASES IN WHICH THERE WAS SOME LABORATORY EVIDENCE OF RECENT INTERCOURSE, ALL THREE METHODS OF SEMINAL FLUID DETECTION WERE POSITIVE (63 PERCENT). IN 27 INSTANCES (12.4 PERCENT), ONLY 1 OF THE FOLLOWING 3 METHODS PROVIDED EVIDENCE OF RECENT INTERCOURSE: SPERMATOZOA WERE DEMONSTRATED ONLY IN THE FRESH PREPARATION IN 4 INSTANCES, IN THE FIXED PREPARATION IN 18 INSTANCES, AND IN 5 INSTANCES ACID PHOSPHATASE WAS THE ONLY SEMINAL FLUID COMPONENT DETECTED. SPERMATAZOA WERE DETECTED IN 75 PERCENT OF THE CASES USING THE UNSTAINED SPECIMEN AND 93 PERCENT OF THE CASES IN THE PRESERVED, STAINED SPECIMEN WHEN THE LABORATORY METHOD SHOWED EVIDENCE OF RECENT INTERCOURSE. MOTILE SPERMATOZOA WERE IDENTIFIED IN THE NATIVE PREPARATION OF FLUID IN 31.7 PERCENT OF THE CASES IF PATIENTS WERE EXAMINED WITHIN 6 HOURS, BUT ONLY IN 18 PERCENT OF THE LATER EXAMINATION CASES. IT IS CONCLUDED THAT DETERMINATION OF ACID PHOSPHATASE AND THE DETECTION OF SPERMATOZOA, BOTH IN THE FRESH AND UNSTAINED SPECIMEN AND IN THE PRESERVED AND STAINED SPECIMEN, ARE OF VALUE WHEN EVIDENCE OF RECENT SEXUAL INTERCOURSE IS COLLECTED. REFERENCES ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED--DAG)