Aim Although chronic pain is common in older adults, its treatment is frequently inappropriate. This problem is particularly prevalent in nursing home residents. We therefore developed an intervention to optimize pain management and evaluated its effects on pain intensity and pain interference with function in nursing home residents in Germany. Methods In a cluster‐randomized controlled intervention, 195 residents of 12 Berlin nursing homes who were affected by pain were surveyed at three points of measurement. A modified German version of the Brief Pain Inventory was used to assess pain sites, pain intensity and pain interference with function in various domains of life. The intervention consisted of separate training measures for nursing staff and treating physicians. Results The primary objective of reducing the mean pain intensity by 2 points was not achieved, partly because the mean pain intensity at baseline was relatively low. However, marginal reductions in pain were observed in the longitudinal assessment at 6‐month follow up. The intervention and control groups differed significantly in the intensity sum score and in the domain of walking. Furthermore, the proportion of respondents with pain scores >0 on three pain intensity items decreased significantly. Conclusions Given the multifocal nature of the pain experienced by nursing home residents, improving the pain situation of this vulnerable group is a major challenge. To achieve meaningful effects not only in pain intensity, but especially in pain interference with function, training measures for nursing staff and physicians need to be intensified, and long‐term implementation appears necessary. Geriatr Gerontol Int 2016; ••: ••–••.