There have been relatively few studies focusing directly on the way mobile payments are used to enhance the quality of the services of MSEs especially those in rural areas and therefore increasing their profitability. MSEs also from the rural areas face problems in settling their day to day transactions as they had to close down their businesses to visit banks to settle their obligations where we have problems of infrastructure and in addition most of MSEs in the rural areas do not have bank accounts. The main purpose of this study was to determine the effects of mobile phone-money transfer services (M-PESA) on the profitability of Micro and Small Enterprises in Bungoma South District. The specific objectives of the study were to; determine the effect of cost reduction, sales revenue and market share by use of mobile phone money transfer services on the profitability of Micro and Small Enterprises. The target population was MSEs in Bungoma South District which consisted businesses such as retail shops, tailoring, chemists, hardware?s, carpentry, metal workers, hair salons, repair services and butcheries. The sampling technique used was multi-stage random sampling where a total of 57 sample size was yielded. Excel Computer Package was used to analyse data which was descriptive and presented in form of graphs, pie-charts, frequency and percentage tables. Some of the major findings included that almost each business own or have used a mobile phone in their business at 98%, education level and duration of running the business has an effect on the profitability of that business. Other major findings were that Mobile Money Transfer services forms the highest percentage of usage among the respondents at 86% as opposed to traditional banking hall and money transfer companies at 10% and 4% respectively as it reduced their transport cost and risks when sending cash. Mobile Money Transfer services were also rated above average with 58% and have assisted MSEs to reduce costs as it reduced the number of times going to the bank i.e. time saving on queuing, it left individuals with more time to run and monitor their businesses one on one, transaction fees are lower than those charged by most banks and it?s easier to use it when paying for clients and customers in their rural areas. Most MSEs also felt that mobile money transfer services have helped to increase sales revenue as mobile phones are mostly used by businessmen to communicate with customers and suppliers and also has helped the business to grow and as a result increased the productivity and profitability of the business. There are many institutions in Kenya that train people on computer usage, but none trains them on mobile phone usage, a technology that is transforming lives for the better in the informal sector. More effort should be made to educate the public especially the MSEs on business benefits of these new technologies. It is commendable that the Kenyan government has removed tax from mobile handsets making mobile phones affordable by many people. Nevertheless, it should also assist in bringing down the cost of airtime further so as to induce most of the MSEs in using the mobile money transfer services. Internet enabled mobile phones are already on the Kenyan market and most MSEs in rural areas do not use these service therefore training is required to enlighten rural people as the internet is important for the import or export of goods, and MSEs that would like to participate in global markets should be given a chance to make informed market choices by being enlightened on internet-based mobile phones. Key Words: Sales revenue, Mobile Phone Money, Transfer system, Profitability, Micro and Small Enterprises.