A consultant is often an effective source of assistance for an agency undergoing change. Community mental health centers (N=80) randomly assigned to treatment and control groups were studied to determine the impact of problem-oriented consultation on problem solution, and the characteristics of both consultant and consultee which are critical in effective consultation. The impact of consultation was assessed by comparing staff assessments from both treatment and control groups on the extent of problem solution. Results indicated no differences in groups at 4 months following consultation, but significant increases in problem solution at 8 months followup for the treatment groups. Among the consultant characteristics found to be related to problem solution were consultant's knowledge, clarification of the problem, presentation of multiple alternatives rather than the "best" solution, and support of the organization's efforts. Specific organization characteristics related to effective consultation outcome were a director and staff receptive to consultation. The findings indicate that consultation research has the potential for helping technical assistance consultation produce the greatest possible benefit to mental health agencies. (MCF)