Adults with diabetes frequently experience diabetes related distress, which is associated with negative health outcomes. Family members are commonly involved in patients’ diabetes self-management. However, family involvement can have helpful and/or harmful effects on patients’ diabetes outcomes. Use of interpersonal strategies to regulate negative emotions may play a role in patients’ interactions with family members and experience of diabetes distress. This study examined the influences of interpersonal emotion regulation and family and friend involvement on diabetes distress among 373 adults with type 2 diabetes. Two separate three-step sequential linear regression models were used to test the main and interactive effects of harmful and helpful family involvement and interpersonal emotion regulation on diabetes distress. Greater use of interpersonal strategies to regulate negative emotions (p = .006) and greater harmful family involvement (p < .001) were significantly associated with greater diabetes distress. Interpersonal emotion regulation moderated the relationship of helpful (p = .007), but not harmful (p = .171) family involvement on diabetes distress. Specifically, greater helpful family involvement was associated with lower diabetes distress among adults with low (p = .017) but not high (p = .419) use of interpersonal strategies to regulate negative emotions. Helpful family involvement appears to be associated with lower diabetes distress, but only among patients with low levels of interpersonal emotion regulation.