Dissertation: Master of Arts in Project Management and EvaluationUnderstanding the gender mainstreaming in water resources management from the insider's perspective is central to determining gender roles of women and men at the community level. Literature indicates that gender mainstreaming is viewed as donor demand rather than management tool of water resources hence lacking the deeper understanding from the insider's perspective. The overall objective of this study was therefore to examine the extent of gender mainstreaming in water resources management project in Gairo District. Specifically, the study analysed strategies used by WARIDI project in gender mainstreaming in water resources management project, evaluated the effect of institutional arrangement on gender relations in water resources management, assessed existing gender dynamics in water resource governance, and explored the constraints of integrating gender in water resource management at the project and community level. The study was conducted in Gairo District, Morogoro Region, a cross- sectional design was adopted during data collection where both qualitative and quantitative data were collected. Content and descriptive analyses were used to analyse data collected, through interviews and focus group discussions. The findings indicate that the position of women and men were recognized by community in project area and some of high leadership positions were held by women in formal water resource management institutions. It was also revealed there are gender inequalities in water resource management particularly in informal institutions. Also the study found that formal and informal institutions were very powerful depending on the sources of water available within the community. It is concluded that WARIDI’s efforts to mainstream gender was partially achieved due to existing gender inequalities. The study recommends WARIDI project to extent efforts to address gender inequalities in natural sources of water at Gairo district.