Background: HIV is associated with an increased risk of aggressive lymphomas. Lymphadenopathy is common at the time of presentation; therefore, we set out to understand the time to lymphoma diagnosis in people with HIV (PWH) undergoing fine needle aspiration (FNA). Methods: A prospective, observational cohort of PWH, age ≥ 18 years, undergoing FNA in Soweto, South Africa was established between September 2021 and December 2022. Participants were followed up for up to 8 months and provided consent for a medical record review. Results: One hundred and forty-six participants were enrolled, including 76 females (52%) with a median age of 40 years and a median CD4 count of 216 cells/μL. TB was the most common diagnosis (n = 62; 42%), followed by lymphoma (n = 21; 14%), of whom 10 (48%) died either prior to diagnosis or initiating chemotherapy. An additional 2 participants (10%) were still awaiting a biopsy confirmation at 8 months. One participant’s FNA was suggestive of both lymphoma and TB. The median healthcare provider interval, the time from presentation to diagnosis, was 85 days. Conclusions: While TB was the most common diagnosis among PWH undergoing FNA, lymphoma was the leading cause of death. As most deaths occurred prior to chemotherapy, interventions to expedite a lymphoma diagnosis in this high-risk population are needed.