Circadian periodicities in activation were studied in relation to married partners' interactional-emotional need fulfillment. Activation was defined as the phenomenological awareness of general bodily energy state or readiness to respond. It was hypothesized that differences in activation would be related to dissatisfaction with need fulfillment. Activation was measured at four designated times of day by alternate forms of the Activation Checklist (Thayer, 1967) and need fulfillment by parallel forms of the Partner Relationship Inventory (Hoskins, 1988). Five couples completed data series that ranged between 27 and 29 days, providing 67 to 106 pairs of data. Cosine curves were fitted to the data for each subject to test for significant circadian periodicities in each variable. A desynchrony score in activation was calculated for the couple at each measurement time and correlated with the interactional-emotional need scores. The data supported the hypothesis for three subjects. Theoretical interpretations and methodological issues are presented.