© 2019 The Author(s). Background: Depression is a common and recurrent condition among older adults and is associated with poor quality of life and increased health care utilization and costs. The purpose of this pilot study was to assess the feasibility of delivering a psychosocial intervention targeting depression, and to develop the procedures to conduct a cluster randomized controlled trial among older adults registered with primary care clinics in poor neighbourhoods of São Paulo, Brazil. Methods: We conducted a pilot study of a two-arm cluster, non-randomized controlled trial. Two primary care clinics adhering to the Family Health Strategy were allocated to either the intervention or the control arm. In the control arm, patients received enhanced usual care consisting of staff training for improved recognition and management of depression. In the intervention arm, alongside the enhanced usual care, patients received a 17-week psychosocial intervention delivered by health workers assisted with an application installed in a tablet. Results: We randomly selected 579 of 2020 older adults registered in the intervention clinic to participate in the study. Among these individuals, 353 were assessed for depression and 40 (11.0%) scored at least 10 on the PHQ-9 and were therefore invited to participate. The consent rate was 33/40 (82%) with a resulting yield of 33/579 (5.7%). In the control arm, we randomly selected 320 older adults among 1482 registered in the clinic, 223 were assessed for depression and 28 (12.6%) scored 10 or above on the PHQ-9. The consent rate was 25/28 (89%), with a resulting yield of 25/320 (7.8%). Of the 33 who consented in the intervention arm, 19 (59.4%) completed all sessions. The mean PHQ-9 at follow-up (approximately 30 weeks after inclusion) were 12.3 (SD = 3.7) and 3.8 (SD = 3.9) in the control and intervention arms, respectively. Follow-up rates were 92 and 94% in control and intervention arms, respectively. Conclusions: Identification and engagement of clinics, randomization, recruitment of individuals, measures, and baseline and follow-up assessments all proved to be feasible in primary care clinics in São Paulo, Brazil. Results support the development of a definitive cluster randomized controlled trial. Trial registration: This study was retrospectively registered with Registro Brasileiro de Ensaios Clínicos (ReBEC), number RBR-5nf6wd. Registered 06 August 2018.