BACKGROUND: Buprenorphine-naloxone treatment engagement for those with opioid use disorder (OUD) is very low. The current randomized effectiveness trial piloted two psychosocial interventions developed to increase buprenorphine-naloxone treatment engagement in 44 individuals with opioid use disorder (OUD) recruited from an OUD treatment clinic. METHODS: Participants were randomized to receive either variable-value contingency management (CM) or a brief substance free activities session plus mindfulness (BSM) cognitive-behavioral intervention at each of the first 4 return visits to the provider. The primary outcome was buprenorphine metabolite in urine and attendance at 2 or more of 4 possible physician visits. RESULTS: Relatively high treatment engagement was observed over 16 weeks with no significant differences in effectiveness between the two intervention arms (p = 0.526). There was slightly better treatment engagement in the CM arm (73 % vs. 59 % engaged in CM and BSM arm, respectively), but this was not statistically significant with n = 22 participants in each group. Treatment engagement was significantly better for those who presented at the clinic with prior buprenorphine exposure: 19 (86 %) of the 22 participants with buprenorphine present in urine at baseline were engaged, whereas only 9 (43 %) out of 21 participants without buprenorphine present in urine at baseline were subsequently engaged (p = 0.004). CONCLUSIONS: Results suggested that patients who are not taking buprenorphine at the start of a psychosocial intervention may require more intensive treatment engagementinterventions than those already taking medication. Satisfaction data were similarly high across the interventions, and qualitative items identified helpful intervention components.