Selection of suppliers is one of the most important decision making problems to management of firms. Selecting the right suppliers significantly reduces the purchasing costs and improves corporate competitiveness. Although all organizations undertake suppliers' selection, most of them fail to find and retain the right suppliers who can perform to the expected levels because they fail to recognise the effects of their selection strategies. This raises issues on the suppliers' selection strategies given that incompetent suppliers are characterised by late deliveries, poor quality products, and wrong delivery, high damages due to mishandling of products, poor communication and high cost which are finally offloaded to customers through product prices. All these are undesirable as they make organizations not realize their pre-set objectives. The main purpose of this study was to establish the effect of partnership negotiation strategies on the selection of suppliers. The specific research objectives were to determine the effect of partnership negotiation strategy on the selection of suppliers. A census of the three private milling companies in Eldoret was taken for the study. The design of the study was correlational method involving a combination of qualitative and quantitative research methodologies. The target population was 460 respondents, out of which a sample size of 210 respondents was drawn from the five major departments in the companies and their suppliers, using stratified random sampling and simple random sampling to select respondents from among company employees, management and suppliers. The researcher then used questionnaires and interviews as research instruments to collect primary data from the respondents. From the Pearson's correlation coefficient findings, the partnership negotiation strategy had positive significant effect on the selection of suppliers (r = .730). The results showed that the partnership negotiation strategy significantly affect the selection of suppliers. The research is an important source of information to millers and other business entities particularly in deciding negotiation strategy to adopt and in reviewing supplier selection policies. Thus the researcher recommended the use of partnership negotiation strategy in the selection of suppliers and further research on impact of adversarial negotiation strategy on the long term relationship between buyers and suppliers