Food security is a major global concern. Food insecurity has insidious effects on the health and development of young children and consequently, adults. The paper assesses the food security status and its key determinants for the rural households of the arid lands of Isiolo in Kenya. A three stage sampling technique was used for respondents (56) selection. Data collected were: demographics, livelihood strategies, food security and livelihood assets. Descriptive and inferential statistical methods and descriptive content analysis were used. Inferential statistics focused on ANOVA, PMC analysis-test and regression analysis. Overall food insecurity was at 75%, with 21% food insecure and 54%vulnerable households. The most food secure households were 2%, and 23%were moderately secure. Household food security was statistically significant(p<.05) with a mean score of (M=2.423, SD=.507). Three key determinants for food security were: natural [t(56) =3.626, p=.000],financial [t(56) = 2.798, p<.05] and human [t(56) =3.181, p <.05] capitals. Livelihood assets accounted for 28.9% (R=0.537, R2=0.289) of the variation in household food security. Coping strategies for food insecurity were: feeding on unbalanced diet, reducing meals, eating low cost food and food relief. Policies that facilitate nutritious food to be within reach and affordable at all times, and investments in human capital are worth promoting for improved household food security.