Excessive alcohol consumption is related to adverse physical and social consequences. Research shows an individual’s own drinking motives (reasons for drinking alcohol) are linked to his or her specific drinking outcomes in a theoretically expected manner. Romantic couples often engage in a “drinking partnership,” where partners reciprocally influence each other’s drinking. Though alcohol consumption partner effects have been studied, partner effects of drinking motives on an individual’s alcohol consumption have not been investigated in romantic couples. We investigated this topic. Romantic couples (N = 203) were assessed once weekly for four weeks using self-report questionnaires. Participants were on average 22.7 years old (SD = 5.5) and were in their relationship an average of 2.3 years (SD = 2.4). Actor-partner interdependence models using multilevel path-Analysis with indistinguishable dyads were conducted, with each motive predicting drinking quantity and frequency. There were significant actor effects for social and enhancement motives; moreover, changes in a partner’s enhancement and social motives predicted change in the individual’s drinking quantity during any given week, but only averaged partners’ enhancement motives predicted the individual’s drinking frequency. Copingwith-anxiety motives had significant actor effects when predicting averaged quantity and frequency; moreover, changes in partners’ coping-with-Anxiety motives predicted changes in drinking quantity. Enhancement and social motives of the partner influenced the drinking quantity and frequency of the actor by way of influencing the actor’s enhancement and social motives. Intervention efforts targeting both members of a romantic dyad on their reasons for drinking should be tested for preventing escalations in either member’s drinking behavior.