The present study deals with psychological, sociological and subjective health aspects of social isolation and understimulation in institutional elderly people. In a controlled study over a 6 month period, a programme was devised in collaboration with residents of a senior citizens apartment building and its staff. The aim of the programme was to increase social activation and to encourage among the elderly an enhanced control over their daily lives. It was agreed that the programme implemented should involve no extra costs, overtime work or external resources. Most psychological and sociological variables were stable over the 6 month period. However, social activity level increased 3-fold in the xperimental group compared with the ontrol group. The E-group also started to attend activities outside the actual programme, and in general spent more time out of doors. Seasonal variations were found in feelings of depression, visits to the country/summer houses, as well as visits by children and neighbours. There were no changes in psychosomatic or psychological complaints indices. However, feelings of restlessness decreased significantly in the E-group over the 6 month period compared with the C-group. There was also a non significant decrease over time in complaints of heart palpitations in the E-group.