Mobile technologies for health (mHealth) represents a growing array of tools being applied in diverse health care settings. mHealth interventions for improving HIV/AIDS care is a promising strategy, but its evidence base is limited. We conducted a formative research evaluation to inform the development of novel mHealth HIV/AIDS care interventions to be used by community health workers (CHWs) in Kampala, Uganda. A mixed methods formative research approach was utilized. Qualitative methods included 20 in-depth interviews (IDIs) and six focus groups with CHWs, clinic staff, and patients. Thematic analysis was performed and selected quotations used to illustrate themes. Quantitative methods consisted of a survey administered to CHWs and clinic staff, using categorical and Likert scale questions regarding current mobile phone and internet access and perceptions on the potential use of smartphones by CHWs. Qualitative results included themes on significant current care challenges, multiple perceived mHealth benefits, and general intervention acceptability. Key mHealth features desired included tools to verify CHWs' task completions, clinical decision support tools, and simple access to voice calling. Inhibiting factors identified included concerns about CHWs' job security and unrealistic expectations of mHealth capabilities. Quantitative results from 27 staff participants found that 26 (96%) did not have internet access at home, yet only 2 (7.4%) did not own a mobile phone. Likert scale survey responses (1-5, 1 = Strongly Disagree, 5 = Strongly Agree) indicated general agreement that smartphones would improve efficiency (Mean = 4.35) and patient care (4.31) but might be harmful to patient confidentiality (3.88) and training was needed (4.63). Qualitative and quantitative results were generally consistent, and, overall, there was enthusiasm for mHealth technology. However, a number of potential inhibiting factors were also discovered. Findings from this study may help guide future design and implementation of mHealth interventions in this setting, optimizing their chances for success.