In recent years, heat transfer enhancement techniques have become one of the main thermal research fields. Helically coiled configuration is more preferable due to their large heat transfer area in a small space, higher heat transfer coefficients and longer operating life. In this research article, theoretical analysis has been conducted to investigate the heat transfer characteristics of single phase laminar flow in a helically coiled tube of small diameter. This work deals with analysis of the coiled tube with different correlations developed for specific conditions by previous researchers. The present analysis follows similar trend for heat transfer coefficient as reported by previous authors. Water is more feasible than nitrobenzene because of its higher heat transfer coefficient.