Drinking motives are among the most proximal factors for drinking behavior and serve as a mechanism through which more distal factors are mediated. However, it is less clear whether drinking motives are precursors of drinking or, in contrast, shaped by previous drinking experiences (reciprocal effects), or both. Moreover, in adults it is unclear whether drinking motives, usually shaped in adolescence, influence each other over time. In this longitudinal study (N = 2440, 47% women, average age 53 years), drinking motives and drinking behavior (i.e., number of drinks on the heaviest drinking day and number of drinking days; both during the past week) were assessed at 2 time points, separated by 3 months. Full cross-lagged regression models revealed that drinking motives were positively associated with drinking behavior over time and that drinking motives are shaped by the number of drinking days (i.e., reciprocal effects). Furthermore, coping and enhancement motives, as well as social and conformity motives, positively reinforced each other. Moreover, social motives were positively associated with enhancement motives over time. In conclusion, drinking motives influence each other over a 3-month period in adulthood and predict drinking behavior over time, making them important candidates for prevention efforts. Drinking motives are likely to be modifiable and might be used to stimulate drinking decrease.