This impact assessment identifies how the water and sanitation initiatives implemented under the Water Sanitation and Infrastructure Branch of UN-HABITAT, have strategically mainstreamed gender aspects in its various initiatives and to identify achievements and impact, challenges, lessons learned and provide recommendations. This gender thematic study is one out three impact studies supported by the WSTF. The other two are Kenya and Nepal Country Impact Assessments. Together these three constitute the first in a series, intended to assist the WSIB in its future plans for regular assessments of its WATSAN initiatives during the coming five years. The study has looked at global, regional and country activities. The country programmes reviewed are implemented in Ethiopia, Ghana,Kenya and Nigeria in Africa; India,LaoPDR, Nepal and Vietnam in Asia and Nicaragua in the Latin America and Caribbean region.