The introduction colonial capitalist economic policies and practices such as land alienation, forced labour and commercial crop production acted as a major catalyst of change on the existing African indigenous subsistence production especially the Agikuyu Women’s Indigenous Knowledge System (AWIKS). This research paper focused on examining the effects of European colonialism on the AWIKS on food crop production from 1902-1918. The study employed descriptive research design and historical trend analysis and it was done in three sub-counties of Kiambu West, namely, Limuru, Lari and Kikuyu. Purposive and snowballing technique was used to get the respondents who were the bearers of the most relevant information. The main source of information was the corroboration of oral interviews, archival records analysis and secondary data. Oral interviews data were analyzed using Statistical Package for Social Scientists (SPSS) and reported using basic simple descriptive statistics. The Women and Development (WAD) theory helped to examine the nature in which the Agikuyu women were integrated in colonial capitalist economy, which explains their marginalization, subordination, oppression and dependency on men. The study found out that during the establishment of colonial rule the Agikuyu people were moved from their indigenous land and were pushed to poor, marginal and unproductive reserve areas where they did not have enough experience and accumulated indigenous knowledge system of the new agro-ecosystem. In addition, most of the drought tolerant food crops were neglected and others destroyed a move that may have led to underutilization of AWIKS on food crop production. This implied that the food supply was compromised and the society became more vulnerable to drought and famine. Therefore, in order to enhance food supply in the households some of the AWIKS on food crop production may be integrated into the modern western agricultural production practices.