Despite the universal scale‐up of pharmacovigilance systems globally, adverse drug reaction (ADR) reporting remains suboptimal among resource‐limited countries. Few studies in sub‐Saharan Africa evaluate the effectiveness of adverse drug reaction (ADR) reporting programmes. A cross‐sectional survey using a self‐administered questionnaire to assess ADR reporting knowledge, attitude and practices among healthcare workers in Namibia's public sector was conducted between September and December 2018. The primary outcome were practices, knowledge and attitude of the respondents towards ADR reporting. Quantitative and qualitative data were analysed using descriptive statistics and thematic analysis, respectively. Of the 197 healthcare workers surveyed, 43.1% were nurses, 63.4% of the respondents knew about the ADR reporting system in Namibia, 76.7% knew the pharmacovigilance/ADR reporting centre in Namibia, while 37.3% had reported an ADR before. Nurses were less likely to be knowledgeable and report ADRs. The independent predictor of ADR reporting was the nursing cadre; adjusted odds ratio (aOR) = 0.17 (95% CI: 0.07, 0.401, P < .01). Pre‐ and in‐service trainings including introduction of electronic reporting platforms were some of the identified ways of optimizing the pharmacovigilance and ADR reporting systems by the respondents. As pharmacovigilance in Namibia relies on spontaneous reporting of ADRs, there is a need for advocacy and workforce strengthening for ADR reporting in the public health sector.