Kenya has faced a wide scale threat of cattle rustling. The menace has been occurring mainly in counties populated by pastoralist groups including the Turkana, Samburu, Maasai, Pokot as well as Kipsigis and Kisii among others. People have been killed, their property lost; some mutilated, injured, and displaced. Security organizations such as the General Service Unit (GSU) and the Anti-Stock Theft Unit (ASTU) among others were mobilized to help curb the danger of cattle rustling yet it has continued to occur in Kenya including Sotik and Borabu Sub counties. The purpose of this study was thus to investigate how effective security agencies were in curbing cattle rustling in the counties of Bomet and Nyamira, Kenya. This study therefore investigated the effectiveness of specialized security agencies in curbing cattle rustling in the Sotik and Borabu Sub-Counties in Bomet and Nyamira Counties in Kenya. A sequential exploratory mixed methods design was used. The target population was all the residents of Sotik and Borabu Sub-Counties (18 years and above) who had information regarding the topic under discourse. They were 284,379 in number. A total of 156 respondents participated. The respondents were drawn through purposive sampling. A questionnaire was used to gather quantitative information while key informant interview guides were used to gather qualitative information from the respondents. The hypothesis was tested using Pearson’s Correlation Coefficient (r) at α =0.05 level of significance. The results obtained from the two sub-counties determined that the deployment of specialized security agencies had a statistically significant effect on curbing cattle rustling. This means that before the deployment of security agencies, the frequency of cattle rustling was relatively high as compared to the periods after their deployment. The reduction was therefore attributed to the constant pursuit and deployment of specialized units such as the ASTU, GSU and Administration Police in the region. The study recommends that the national government should expand the presence and activities of specialized security agencies in regions with a history of high cattle rustling rates, focusing on areas with the highest correlation between agency presence and rustling reduction. The government should also implement targeted training programs for specialized security personnel to equip them with the necessary skills and knowledge for addressing the unique challenges associated with cattle rustling.