This study aimed at assessing cashflow as a determinants of corporate investment decisions of firms listed on Nairobi securities exchange in Kenya. The objective of the study was assessing the effect of cash flow on corporate investment decisions of firms listed at the NSE. The study used both primary and secondary data. The study adopted descriptive research design and the target population was 64 firms listed on the Nairobi Securities Exchange (NSE). Data was analyzed using descriptive statistics, correlation analysis and regression analysis using SPSS version 23. The study used simple linear regression models to establish the relationship between dependent and independent variables. The study established that firms had enough cash for its shareholders, the firm had a clear debt management policy. The study concludes that cash flow affects corporate investment decisions of firms listed at the NSE. There was enough cash for shareholders and there was a clear debt management policy. The study recommends that listed firms that have no debt policies should ensure that the management put in place operational debt management policies.