Food security remains a major challenge for most rural households in Kenya especially those in arid and semi arid areas. Women play a crucial role as primary food producers and custodians of household food security. They however face many constraints in their endeavor to secure food for their households. Women, lack access to extension education, land and credit and these challenges are exacerbated by effects of climatic variability, especially drought. In response to the difficulties facing them, women in Mwala have formed organizations (women groups) as safety-nets to help them face these challenges collectively rather than as individuals. This study research was designed to investigate how women's participation in the groups influences them to overcome constraints related to their household food security. The study used a cross sectional survey design. A sample of 156 respondents was selected through simple random sampling, with 94 women farmers being group members and 62 non group members. Ten key informants were purposively sampled from group leaders of the most active women groups influenced in agricultural activities to participate in a focus group discussion. The data was analysed using SPSS package version 17 and presented using frequencies, percentages, multiple regression, and Spearman's Rank Correlation Coefficient. The study revealed that household food security is significantly and positively influenced by participation of women farmers in women groups (F=9.980, p<0.001), that the level of intensity of participation in group activities did not significantly influence household food security (x2=.112) and that linking with outside agencies was positively and significantly correlated to group performance measured in terms of benefits availed to the members through their groups.