It is a great need of gender mainstreaming in the process of law making to ensure equality between men and women. This was stipulated in the Vietnam's Law on Gender Equality as well as in the international conventions. The Law on Irrigation that is being .elaborated to submit the National Assembly for approval and issuance is not an exceptional case of gender mainstreaming mentioned above. Although it is a specialized law of a sector, its subject and scope has influence on farmers, of which rural women depend significantly on agricultural production. This article outlines the context and the need for gender mainstreaming in elaboration of the Law on Irrigation, as well as discussion on issues related to gender mainstreaming. The authors also offer some recommendations to elaboration of the Law on Irrigation to ensure it is fully integrated with gender perspective.