Income diversification is considered one of the important household strategies for securing rural livelihoods. We investigate its patterns and determinants using data on 1,747 farm households collected in 2007-2008 from six regions in rural Senegal and Kenya. The empirical investigation shows that the regional variation in income diversification does not follow any clear patterns, with push and pull determinants acting concurrently within and between regions. Therefore, policies on income diversification need to be tailored to meet the development needs of specific regions. More generally, income diversification is significantly associated with household asset endowments, demographic factors, accessibility to rural towns, migration opportunities, and perceptions on food security.