A PREVENTION PROGRAM IS AN ORGANIZED FORM OF SOCIAL INTERVENTION DESIGNED TO REDUCE THE OCCURRENCE OF DELINQUENCY AMONG A CERTAIN CLASS OF INDIVIDUALS USING A VARIETY OF MEANS. THE QUEBEC, CANADA PREVENTION PROGRAMS STUDIED ARE RUN BY FEDERAL AND STATE SOCIAL SERVICE ORGANIZATIONS; THEY EXCLUDE ENGLISH-SPEAKING PROGRAMS, POLICE PROGRAMS, AND PROGRAMS WHICH TRANSFORM THE ENVIRONMENT TECHNOLOGICALLY. MOST OF THE PROGRAMS ARE CONCENTRATED IN MONTREAL. ANALYSIS OF STRATEGIES USED BY PROGRAMS INDICATES THAT A MAJORITY OF THE PROGRAMS HAVE THEIR CENTERS IN ECONOMICALLY COMFORTABLE AREAS, THAT MOST ARE DIRECTED AT ADOLESCENTS UNDER 18 YEARS OLD, AND THAT ONLY 62 PERCENT ARE SPECIFICALLY CONCERNED WITH DELINQUENCY, ATTEMPT TO COUNTERACT STIGMATIZATION, AND PRESUME FAMILIAL PROBLEMS AND ECONOMIC DISADVANTAGES AMONG CLIENTS. A STUDY OF TACTICS SUGGESTS THAT MOST PROGRAMS ARE SHORT-LIVED (1 YEAR) AND THAT ALMOST ALL PROGRAMS, WHETHER PUBLIC OR PRIVATE, ARE SUBSIDIZED BY GOVERNMENT FUNDS (53 PERCENT FEDERALLY), ALTHOUGH MANY ALSO RECEIVE PRIVATE ASSISTANCE. MOST PROGRAMS ARE ADMINISTERED PROFESSIONALLY WITHOUT VOLUNTEERS. HALF OF THE PROGRAMS SPECIALIZE IN CARE-TAKING (CRISIS INTERVENTION, SPONSORSHIP, HOUSING) AND HALF PROVIDE ASSISTANCE IN THE FORM OF INFORMATION OR REFERRALS. OVERALL, DELINQUENCY WHICH ARE MEANT FOR OFFICIAL OR POTENTIAL DELINQUENTS OF EITHER SEX AND OF ANY AGE FROM DISRUPTED FAMILIES AND DISADVANTAGED CIRCUMSTANCES, AND WHICH USUALLY INVOLVE COMPLETE CUSTODIAL TECHNIQUES, OR AS COMMUNITY PREVENTION PROGRAMS DESIGNED FOR POTENTIAL OFFENDERS OR THE GENERAL POPULATION, USUALLY MEMBERS OF BOTH SEXES UNDER 18 YEARS OLD WITH PROBLEMS ARISING FROM LACK OF SOCIOECONOMIC OPPORTUNITY AND FROM STIGMATIZATION. BOTH TYPES OF PROGRAMS MAY SERVE VOLUNTARY OR REFERRED CLIENTS AND MAY BE LOCATED IN PROSPEROUS OR MARGINAL NEIGHBORHOODS. EXTENSIVE TABLES AND APPENDIXES, AS WELL AS SPECIAL DOCUMENTS ARE PROVIDED. --IN FRENCH. (KMD)