摘要:Cost overruns have provided a significant challenge in the construction industries of both developed and developing countries. The purpose of this study was to investigate the influence Subcontractor Oversight on Construction Cost Overruns of real estate projects in Nairobi and Kisumu Counties. The study was guided by objective, to establish the extent to which subcontractor oversight influence real estate construction projects cost overruns. The research adopted descriptive survey and correlational research designs. The study targeted a population of 4000 project professionals that constituted 7 professionals from active real estates in Nairobi and Kisumu Counties and 10 key informants from the real estate industry. Using the Krejcie and Morgan table of sample size determination, the sample size for this study was 351. The study then adopted stratified, simple random and purposive sampling methods to select appropriate sample sizes from the study population strata. Structured questionnaire was the main instrument for data collection, supported by interview guide. Hypothesis was tested at 伪=0.05 level of significance and the results were: H0: There is no significant relationship between subcontractor oversight and real estate construction projects cost overruns was rejected since P=0.000<0.05. Considering the study findings and conclusions, the following recommendations were made: Project professionals and other relevant real estate project stakeholders should encourage comprehensive subcontractor oversight as critical concerns in assembling pertinent information and creating avenues that could be utilized to reduce real estate construction projects cost overruns.