Small and Medium Enterprises (SME) play a significant role in economic development. The requirements of capital and manpower in SME is not so significant. These are the motivations and rationale for entrepreneurs with shortage of fund to run SMEs. Management of SME is also simple as compared with large scale businesses. Still SMEs suffer from some limitations like poor management, financing, unfriendly regulations, low patronization etc. Most of the advanced business tools developed so far target large scale industries. SMEs need to make those tailored with the typical nature of SMEs. This piece of work covers a little bit detail on the issues. Different definitions of SMEs in different countries have been presented here to have a comparative picture. Performance measurement and financing in SME is covered in detail. Real life experience of two entrepreneurs are presented to give it a practical look. It also covers a discussion on BASEL II and its application in SMEs. Finally, the use of mathematics in SMEs is presented with the computation of recovery of loan in an assumed situation. Young researchers and entrepreneurs, involved in SMEs, will be benefited using this write-up.