Competitive pressures are increasing demands on managerial performance and, thus, on creating effective management development programs. The purpose of this study was to compare group and individual approaches to developing line and middle managers. The Managerial Tools and Managerial Training Simulator programs were used, with 256 managers participating. We examined the following five soft management skills: effective goal setting, giving feedback and evaluating performance, accepting feedback as a manager, management coaching, and leading discussions and team meetings using a facilitative leadership style. After both types of development programs, both groups of managers showed improvements in developing skills as assessed by their subordinates. At the first measurement, individual and group development resulted in the same positive increase in subordinates' perceptions. However, in terms of a long-term effect (the second measurement), this positive increase was maintained for the individual development programs but not group programs, where it decreased. Thus, the effect of the individual development programs appears to be longer-term. Overall, we found no significant difference between line and middle managers - both groups responded similarly to the development activities. Regarding developing individual skills, the smallest change was found in the ability to set goals and provide feedback. The most considerable change was the ability to accept feedback, coach, and facilitate. This research provides information for specialists in education and development and may help select appropriate leadership development tools, particularly for individual programs with longer-term impacts.