Very few studies have used longitudinal data to examine whether age variations in the sense of control are due to ageing effects or cohort differences. With data from two waves of the Norwegian NorLAG study, with 2673 respondents aged 40 to 75 we ask: Does the sense of control decline over a 5-year period? Are there factors that accelerate the decline or slow it? We find that while cross-sectional comparisons indicate increases in sense of control up to age 75, longitudinal analysis show little to no change over 5 years. Only those 75 and older experienced a significant decline over the next 5 years. Physical health and agentive orientation at baseline can impede or accelerate decline in the sense of control. We also find that decline in sense of control starts 15 years later in this Norwegian sample than in similar studies in the United States, and discuss this finding in light of differences in welfare systems for elderly in the two countries.