People experience autonomy when they perceive their behaviour to be volitional rather than driven by external controls. Previous research has studied autonomy in relationships at a general level, focusing on people's motivations to maintain their romantic relationships, as measured by the Couple Motivation Questionnaire (CMQ; Blais et al., J Personal Soc Psychol 59:1021–1031, 1990). To supplement the CMQ, we developed the Motivations for Relational Activities (MRA) scale, which assesses the extent to which people feel autonomous and controlled in a variety of specific relational activities. The purpose of this study is to examine the unique contributions of general motivations to maintain a relationship (CMQ) and motivations toward specific relational activities (MRA) in the prediction of relationship well-being. Results showed that the MRA and CMQ both independently and significantly contributed to the prediction of relationship well-being (i.e., commitment, intimacy, satisfaction, and vitality within the relationship) and were differentiated by their associations to dimensions of personality and attachment.