Water, sanitation and hygiene (WASH) interventions significantly reduce health risks in low- and middle-income countries. Many rely on women, but the extent of womens engagement remains undocumented. Here we conducted a re-review of papers from two systematic reviews that assessed the effectiveness of water, sanitation and/or handwashing with soap interventions on diarrhoeal disease and acute respiratory infections to assess womens roles in WASH research and intervention activities. A total of 133 studies were included. Among studies that specified gender, women were the most sought-after group for engagement in research (n = 91/132; 68.9%) and intervention (n = 49/120; 40.8%) activities. Reporting time burden for research (n = 1; 1%) and intervention activities (n = 3; 2.5%) was rare. All interventions were classified as gender unequal (36.7%) or gender unaware (63.3%) according to the World Health Organization Gender Responsiveness Assessment Scale, indicating exploitative engagement. Women play a critical but instrumentalized role in WASH, and both research and interventions need to change to enable, and not hinder, gender equality.