The article presents a panoramic view of the evolution and growth of the Primary Mental Health Project (PMHP), an innovative schoolbased program for early detection and prevention of school-maladjustment problems. It consists of 3 major sections: (a) a historical account of PMHP, identifying the problems it seeks to address, its rationale, its beginnings, and its growth over the years; (b) a description of how the current PMHP program works and of the program modifications that have been developed to meet practical problems; and (c) a consideration of PMHP's accomplishments and contributions, as well as implications for future steps to promote the well-being and adjustment of young (school) children.The Primary Mental Health Project (PMHP) is an innovative program for early detection and prevention of school-adjustment problems (Cowen, Trost, Lorion, Dorr, Izzo, & Isaacson, 1975). It started 23 years ago in response to the fact that the incidence of school maladjustment in young children far exceeded mental health's ability to provide help. Through the use of early-detection and screening devices, which PMHP has developed over the years, the program identifies primary grade children with early school-adjustment problems. Once identified, those youngsters receive prompt, effective helping services from carefully selected, trained, nonprofessional child-aides. The latter, working under close professional supervision, increase tenfold the number of children served. The project addresses behavior and adaptive problems (e.g., aggression and withdrawal) that interfere with effective learning. Program evaluation studies have shown that the approach helps many young children to a richer, more productive school experience. As a result of PMHP's active and recent dissemination, the project model has been adopted by some 50 + school districts and 300 + schools across the country.When all is said and done, perhaps PMHP's most distinctive features are that it has survived 23 years and, in the process, has perceptibly influenced how school mental health services are conceptualized and delivered. Looking retrospectively at PMHP's cumulated writings, one sees that individual papers ad-