Water, sanitation, and hygiene interventions significantly reduce health risks in low- and middle-income countries. Many rely on women for their success but the extent of women’s engagement remains unclear. We conducted a re-review of papers from two systematic reviews that assessed effectiveness of water, sanitation, and/or handwashing with soap interventions on diarrheal disease and acute respiratory infections to assess women’s roles in WASH research and intervention activities (PROSPERO registration: CRD42022346360). 133 studies were included. Among studies that specified gender, women were the most targeted 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-blind (63.3%) according to the WHO Gender Responsiveness Assessment Scale, indicating exploitative engagement. Women play a critical but instrumental role in advancing WASH, which requires change to enable, not hinder, gender equality.