One month after their quit date, 221 Ss completed a shortened Partner Interaction Questionnaire (PIQ) in which they reported the frequency of 10 positive and 10 negative behaviors performed by a spouse or romantic partner in response to their quitting attempt. A subset, using the same instrument, reported expectations of support prior to quitting. The ratio of received positive/negative behaviors was a consistently better predictor of abstinence than were the frequencies of either positive or negative behavior alone, with higher ratios associated with abstinence. In addition, partners were less interactive than expected but performed more positive behaviors than expected. The overall pattern of results suggests that the context of a relationship mediates the impact of specific supportive or nonsupportive behaviors. Psychometrics for the 20-item PIQ are presented.