General practitioners (GPs) need advanced skills in geriatric assessment to be competent to treat the increasing number of elderly patients. Continuing medical education in geriatrics for GPs is heterogeneous, and not assessed for effectiveness. In this study we compared the educational effects of three geriatric post-graduate training methods on GPs. GPs in the health district of the Nijmegen University Medical Centre (The Netherlands) were offered a variety of training options in geriatric assessment: (1) a formal one-day teacher centered conference (TCC), (2) an interactive GP-centered day of workshops (GCW), and (3) participation in a project of knowledge translation, linked to a research project of geriatric intermediate care (GKT). Pre-post measures were taken of the attitudes of GPs towards the elderly (Aging Semantic Differential, 1969), attitudes towards geriatric patients (Maxwell & Sullivan, 1980; Rosencranz & McNevin, 1969) and geriatric competencies (Robinson, Barry, Renick, et al., 2001). After training, neither the attitudes towards the elderly nor geriatric patients changed in any of the three groups. The TCC did not show a significant change in perceived competencies, while the GCW and GKT group improved. A formal large group conference is ineffective in improving GPs' geriatric assessment skills, while small interactive workshops and participation in a project of knowledge translation are equally effective. None of the three training methods improved or worsened attitudes toward the elderly in general or the geriatric patients in particular.