Objectives We performed a mixed‐methods study to explore the motivations associated with blood donation by donors with known, but undisclosed HIV‐positive status and ARV use (HIV+/ARV+), seeking potential strategies to reduce such donations and mitigate risk for blood recipients. Here, we report predominantly the qualitative component. Background A safe and sustainable blood supply is dependent in part, on effective pre‐donation donor assessment. We previously described failure by HIV+/ARV+ blood donors to disclose their status. Such donations may lead to transfusion‐transmitted HIV. Methods The social ecological model provided the conceptual framework for this study. Previously identified HIV+/ARV+ donors were invited to complete a survey (including a validated stigma scale) and qualitative interview, which underwent inductive and deductive thematic analysis. Results We uncovered two primary motivational paths to HIV+/ARV+ blood donations: privacy and altruism. The latter included a motivation not previously reported in the literature: donating specifically for other people living with HIV (PLWH). The other primary factor was a lack of privacy. These accounts often included donors encountering donation opportunities when accompanied by people to whom they had not and did not plan to disclose their HIV status. Most were highly confident their donations would be identified as HIV‐positive and discarded. Conclusion We demonstrated a complex interaction between individual, social, cultural, and structural/policy factors in blood donations by PLWH who take ARV. Recommendations to limit HIV + ARV+ donations include: (1) Targeted communication strategies to increase knowledge among PLWH of their deferral from blood donation—without increasing stigma, and (2) development of procedures to assist those who feel unable to opt‐out of donation due to privacy concerns.