Posttraumatic stress disorder (PTSD) is linked to negative relationship outcomes, but the relational processes that link specific PTSD symptoms to these outcomes over granular periods are not well understood. The current study used a daily diary methodology to investigate the associations between specific PTSD symptoms (i.e., anger, avoidance, reexperiencing, hyperarousal, and numbing) and proximal indices of relationship functioning (i.e., accommodation behaviors, disclosure, intimacy). Participants were members of 64 couples, each comprising a male service member (SM) and female romantic partner (RP), who completed daily assessments of PTSD symptoms and indices of relationship functioning for 2 weeks. The results suggest a somewhat unique role of anger on relationship dynamics: Although mean levels of PTSD symptom clusters were associated with negative relationship outcomes at the bivariate level, daily fluctuations in anger were uniquely related to accommodation behaviors and SM‐ and RP‐reported intimacy in multilevel models, Bs = −0.08–0.50). These findings highlight the importance of considering the differential role of specific PTSD symptoms, like anger, in dyadic interventions for PTSD; several strategies for doing so in the context of contemporary evidence‐based treatments are discussed.