We propose that perceived partner concealment, self-concealment from one's partner (i.e., keeping secrets from one's partner), and trust in one's partner form a reciprocal cycle in romantic relationships. In Study 1, participants in a romantic relationship (N = 94) completed a two-time point survey within a span of 8 to 10 weeks. Results revealed that perceived partner concealment was associated with a loss of trust in partner, and low trust in partner was associated with an increase in self-concealment from one's partner. Furthermore, the association between perceived partner concealment and self-concealment from one's partner was mediated by trust. In Study 2, couples (N = 50) completed daily records for 14 consecutive days. Multilevel analyses indicated that on the days the individuals reported more self-concealment, their partners reported lower trust in them. Moreover, on the days the partners reported lower trust, the partners also reported higher self-concealment. These findings suggest that self-concealment in romantic relationships can create a reciprocal cycle that involves loss of trust and more self-concealment between partners, which would slowly deteriorate the relationship well-being. Copyright © 2012 John Wiley & Sons, Ltd.