Food security is a major global concern. Household food insecurity has insidious effects on the effects on the development of young children and consequently, adults. A disconnect between poverty reduction and the persistence of hunger among the world population has brought new attention to the mechanisms governing access to food in the developing world. Kenya is one of the developing countries threatened by food insecurity. The study assessed the food s urity status and its key determinants for the rural households of the high rainfall zone of Murang'a, semi-arid lands of Kitui and arid lands of Isiolo in Kenya. The objectives were to: e ermine households' food security, establish the main determinants and assess the coping strategies for households' food insecurity. A three stage sampling technique was used for 384 re pondents' selection. Data collected were household: demographics, livelihood strategies, food security and livelihood assets. Descriptive and Inferential Statistical methods and descriptive Content Analysis were used. Inferential statistics analytical methods were: analysis of variance (ANOVA), Pearson moment correlation (PMC), t-test and regression analysis. Overall food insecurity was 48%, but this varied across the agro-ecological zones, with the most affected being the semi-arid lands of Kitui at 81 % to arid lands of Isiolo at 75%. The most food secure was the high rainfall zone of Murang'a at 77.2%. Food security was ignificantly different (p<0.05) across the agro-ecological zones [F (2, 381) = 41.01, P<0.05]. Agriculture was the main source of livelihood to 79% households. Livelihood assets accounted for 37.2% (R=0.610, R2=0.372) of the variability of household food security. Overall key eterminants for household food security were: natural [t(384)= 9.364, P=0.000], physical [1(384)= 3.523, P=0.000] and financial [t(384)= 3.120, P<0.05] capitals. The main determinants for the specific agro-ecological zones were: high rainfall zone of Murang'a; natural [t(228) =8.412, P=0.012], physical [(228) =3.778, P=0.000] and financial [t(228) =2.784, P=0.002] capitals, semi-arid lands of Kitui; financial [t(!OO) =7.67, P=0.000], natural [t(lOO) = 10.294, P<0.05], social [t(l 00)=3.42, P<0.05] capitals and arid lands of Isiolo; natural [t(56) =3.626, P=0.000], financial [t(56) = 2.798, P<0.05] and human [t(56) =3.181, P<0.05] capitals. Coping strategies for food insecurity were: eating low quality food, reducing meals, purchases and food relief Contextualization of interventions is necessary in addressing the perennial food securiry in the study areas. Policies that facilitate food to be within reach and affordable at all nmes are worth promoting for improved security.