Interpersonal and social rhythm therapy (IPSRT) is an evidence-based treatment for bipolar disorder. It combines two distinct psychosocial interventions, interpersonal psychotherapy (IPT) and social rhythm therapy (SRT), into a seamless whole to treat acute bipolar episodes and prevent mood episode recurrence. The IPT component focuses on connections between mood and relationships, with an emphasis on resolving an agreed-upon interpersonal problem area. Therapists also use techniques from IPT to address grief for the lost healthy self, that is, mourning losses associated with having been diagnosed with bipolar disorder. SRT is a behavioral intervention that helps patients establish more regular daily social rhythms to stabilize underlying disturbances in circadian rhythms intrinsic to bipolar disorder. SRT relies on a tracking form, the social rhythm metric, to monitor and modify daily routines. Psychoeducation about bipolar disorder and circadian rhythms is also woven into IPSRT. This chapter describes the rationale for IPSRT, empirical evidence supporting its efficacy, and psychotherapeutic strategies associated with its implementation.