Background The integration of patient–reported outcome measures (PROMS) into health care delivery systems is being increasingly recognized as an important component of quality, person-centered care, especially for chronic illnesses like congestive heart failure (CHF). However, while PROMS are increasingly being used to follow up CHF patients in high income countries, their use in sub-Saharan Africa is still limited. We adapted the Kansas City Cardiomyopathy Questionnaire (KCCQ-23), an internationally validated, CHF-specific PROM and tested its use in measuring outcomes in an outpatient CHF clinic at a cardiac referral hospital in Tanzania. Methods Adaptation of the KCCQ-23 included translation into Swahili by linguistic experts, in-depth cognitive debriefing in native Swahili–speaking CHF patients, and input from Tanzanian Cardiologists, PROMS experts, and the tool developer. Using a cross-sectional design, we tested the usability and observed the results of the translated KCCQ-23 in a convenience sample of 60 CHF patients attending outpatient clinic at the Jakaya Kikwete Cardiac Institute (JKCI) in Dar es Salaam. Results The survey was successfully completed by 59 (98.3%) of 60 enrolled participants. The mean (SD) age of participants was 54.9 (14.8) years (range 22–83), 30.5% were women and 72.2% had class 3 or 4 New York Heart Association (NYHA) symptoms at enrollment. The overall KCCQ-23 score was low, with a mean (SD) score of 21.7 (20.4) indicating generally very poor to poor patient reported outcomes in this population. The mean (SD) scores for the specific KCCQ-23 domains were 15.25 (24.2) for social limitation, 23.8 (27.4) for physical limitation, 27.1 (24.1) for quality of life and 40.7 (17.0) for self-efficacy. No socio-demographic or clinical characteristics were associated with their overall KCCQ-23 scores. Comparing the short version (KCCQ-12) with the full KCCQ-23 revealed excellent correlation between the two (r = 0.95; p < 0.0001). Conclusions We successfully translated a validated tool, the Swahili KCCQ, for use in improving the care of patients with CHF in Tanzania and a broader population of Swahili–speaking patients. Both the Swahili KCCQ-12 and KCCQ-23 can be used, with similar outcomes. Work to expand the use of the tool in the clinic and other settings is planned.