Background: Hope or hopefulness enhances coping and improves quality of life in persons with chronic or incurable illnesses. Lack of hope is associated with depression and anxiety, which impact negatively on quality of life. In Tanzania, where HIV prevalence is high, the rates of depression and anxiety are over four times higher among people living with HIV (PLH) compared to persons not infected and contribute annual mortality among PLH. Tanzania has a shortage of human resources for mental health, limiting access to mental health care. Evidence-based psychosocial interventions can complement existing services and improve access to quality mental health services in the midst of human resource shortages. Facilitating hope can be a critical element of nonpharmacological interventions which are underutilized, partly due to limited awareness and lack of hope measures, adapted to accommodate cultural context and perspectives of PLH. To address this gap, we developed and validated a local hope measure among PLH in Tanzania. Methods: Two-phased mixed methods exploratory sequential study among PLH. Phase I was Hope-related items identification using deductive, inductive approaches and piloting. Phase II was an evaluation of psychometric properties at baseline and 24 months. Classical test theory, exploratory, confirmatory factor analysis (CFA) were used. Results: Among 722 PLH, 59% were women, mean age was 39.3 years, and majority had primary school level of education. A total of 40 hope items were reduced to 10 in a three-factor solution, explaining 69% of variance at baseline, and 93% at follow-up. Internal consistency Cronbach's alpha was 0.869 at baseline and 0.958 at follow-up. The three-factor solution depicted: positive affect; cognition of effectiveness of HIV care; and goals/plans/ future optimism. Test-retest reliability was good (r = 0.797) and a number of indices were positive for CFA model fit, including Comparative Fit Index of 0.984. Conclusion: The developed local hope scale had good internal reliability, validity, and its dimensionality was confirmed against expectations. The fewer items for hope assessment argue well for its use in busy clinical settings to improve HIV care in Tanzania. Hope in this setting could be more than cognitive goal thinking, pathway and motivation warranting more research. Trial registration: The intervention was registered in USA ClinicalTrials.gov on September 26, 2012, Registration number: NCT01693458.