Abstract: Several studies have brought up the following variables as determining factors of out of pocket health spending such as income levels, employment status, cost of medical services and access to health financing/health insurance. This study’s specific objectives include: to investigate, examine and establish the association between income levels, employment and cost of treatment and access to health insurance/ health insurance status on Out-of-Pocket medical expenditures among out patients at the following selected health facilities in Nairobi county Kenya. A mixed research design technique was used to collect data which involved the use of both primary and secondary data sources. A structured questionnaire was used to collect primary data. Data collected for this study was analyzed using both qualitative and quantitative techniques with SPSS software. The target group of this study was the prior mentioned hospitals. The accessible population of the study was 115 respondents. The study’s pilot test results indicate that the survey instruments were reliable and consistent.