This document notes that counselors are increasingly called upon to develop activities intended to prevent rather than remediate. It describes a model by which counselors can systematically develop, implement, and then evaluate a preventive intervention, and it suggests that the most beneficial approach is group planning with the involvement of all school-related persons. Included at each step of the planning model are examples of previously developed plans. The 10-step procedure for the planning of primary prevention interventions presented in this document is based on George Albee's incidence formula in which Albee saw the occurrence of mental illness as related to the six components of organic factors, stress, exploitation, coping skills, self-esteem, and support groups. For each step in the 10-step process, the explicit task of the step is identified and three examples of the step are given. Examples are from interventions for enhancing the mental health of primary students from low-income families, at-risk students attending an inner city high school, and elementary teachers of students at-risk. References are included; additional materials are appended. (NB)