This tool kit assists staff and consultants of the Asian Development Bank (ADB) in conceptualizing and designing gender-responsive projects in the energy sector. It guides users in key questions to be asked and data to be collected during project preparation. It also offers a menu of entry points in designing project outputs, activities, inputs, indicators, and targets that integrate key gender issues identified during the gender analysis. The tool kit is broken down into key subsectors of ADB's energy sector investments---transmission and distribution, rural electrification, energy efficiency, and renewable energy. Case studies from ADB energy projects have been included to illustrate good practices in mainstreaming gender in energy sector.