Factors determining vocational success and failure for mentally retarded persons are reviewed and implications for teacher education addressed. The history of vocational programs for this population is traced, and problems noted in research regarding vocational fitness (including lack of standardized projective vocational tools). Among factors cited as related to success are personality traits, environment, psychomotor efficiency, and personal and social adjustment. Characteristics of vocational failure are said to include social immaturity and community adjustment problems. Research on vocational predictors, largely inconclusive, is reviewed. Implications for teacher education are explained to include curriculum emphases on social and personal adequacy and client and employer counseling. The paper concludes with a brief summary of Project PREM (Preparing Regular Educators for Mainstreaming) which developed a competency based teacher education module on career education. (CL)