Despite many water, sanitation, hygiene (WASH) and other environmental health challenges in sub-Saharan Africa, little is known about interactions involving scientists, journalists and the public to aid public understanding of the relationship between WASH and health. Using purposive sampling, we conducted key informant interviews and focus group discussions with scientists, journalists and members of the public in Ghana and Uganda to identify issues associated with the promotion of public engagement with WASH and environmental health issues. An inductive thematic analysis was used to explore the evidence, challenges and opportunities of public engagement. The effectiveness of public engagement was constrained by poor interaction between scientists and journalists and limited understanding among the public on WASH and other environmental health issues. Challenges identified included inadequate scientists–journalists collaborations, scientists' lack of time, pressure from media organizations and concerns about journalists' inadequate capacity to communicate environmental issues due to lack of training. Possible solutions included increased interactions, science communication training and using public information officers as knowledge brokers between scientists and journalists to boost public engagement with WASH and other environmental health issues. Our study contributes to the literature on the need to actively engage the public with WASH and other environmental health concerns.