LOS ANGELES AND BOSTON WERE CHOSEN FOR COMPARATIVE ANALYSIS ON THE BASIS OF THEIR QUITE DISTINCT STYLES OF LIFE. THE UNIFORM CRIME REPORTS FOR 1967 SHOW THAT THE REPORTED FORCIBLE RAPE RATES ARE ALSO STRIKINGLY DIFFERENT: THE RATE FOR THE LOS ANGELES AREA WAS 35.4 PER 100,000 POPULATION, WHILE THE COMPARABLE RATE FOR BOSTON WAS 7.7 PER 100,000--ONE-HALF THE OVERALL RATE FOR THE U.S. AND ONE-FIFTH THAT OF LOS ANGELES. IN BOSTON, FORCIBLE RAPE CONSTITUTES ABOUT 0.5 PERCENT OF THE INDEX CRIMES; IN LOS ANGELES, THE OFFENSE ACCOUNTS FOR SLIGHTLY MORE THAN 1 PERCENT OF INDEX CRIMES. THE DISCREPANCY IN FORCIBLE RAPE RATES IS THEREFORE SPECIFIC TO THE OFFENSE ITSELF AND NOT A FUNCTION OF DIFFERENT PREVAILING RATES OF CRIME IN THE TWO CITES. A RANDOM SAMPLE OF POLICE REPORTS ON FORCIBLE RAPE CASES IN THE TWO CITIES DURING 1967--136 CASES FROM LOS ANGELES AND 46 FROM BOSTON--WAS STUDIED. THE DATA SHOW THAT A CONSIDERABLY BROADER DEFINITION OF THE CRIME WAS APPLIED IN LOS ANGELES: ALL CASES IN WHICH THE PERSON APPEARS TO BE SEEKING 'SEXUAL GRATIFICATION' WERE COMMONLY CLASSIFIED AS FORCIBLE RAPE. THIRTY CASES REPORTED IN LOS ANGELES, THEREFORE, WERE DISCARDED FOR PURPOSES OF THE STUDY, AS THEY CONSISTED OF NUISANCE BEHAVIOR RATHER THAN FORCIBLE RAPE PER SE. STATISTICALLY SIGNIFICANT DIFFERENCES IN REGARD TO FORCIBLE RAPE OFFENSES INCLUDED: (1) MORE RAPE OFFENSES WERE COMMITTED DURING WEEKENDS IN LOS ANGELES THAN IN BOSTON; (2) BOSTON SHOWED A CLEAR SEASONAL TREND, WITH A MAJORITY OF RAPES OCCURRING BETWEEN MAY AND AUGUST, WHILE LOS ANGELES RAPES WERE DISTRIBUTED RELATIVELY EVENLY OVER THE 12 MONTHS; (3) MULTIPLE OFFENDER RAPES WERE MORE LIKELY TO BE COMMITTED IN LOS ANGELES THAN IN BOSTON; AND (4) THE OFFENDER WAS A TOTAL STRANGER TO THE VICTIM MORE OFTEN IN BOSTON THAN IN LOS ANGELES. MORE YOUNG VICTIMS WERE IN LOS ANGELES, AND MORE YOUNG OFFENDERS IN BOSTON. THE RESEACHERS ATTRIBUTE SOME OF THESE DIFFERENCES, NOTABLY THE YOUNGER RAPE VICTIMS, HIGHER NUMBER OF WEEKEND RAPES, AND GREATER NUMBER OF ACCOMPLICE RAPES IN LOS ANGELES, TO THE MORE PERMISSIVE SEXUAL CLIMATE. IMPROVEMENT OF BASIC DATA, ESPECIALLY IN TERMS OF MORE CONSISTENT OFFENSE CLASSIFICATION, AND FURTHER COMPARATIVE STUDIES ON FORCIBLE RAPE ARE URGED BY THE AUTHORS. REFERENCES ARE PROVIDED.