The need for efficient cooling techniques has motivated researchers to focus into heat transfer and flow behavior of various configurations of finned surfaces. Inclined rectangular fin is found to be an effective vortex generator for heat transfer augmentation, wherein longitudinal vortices is generated and keeps intensity at far downstream. It is expected that the heat transfer from the endwall and the fin surface can be improved and hence we have identified this configuration as very promising. Rectangular fins of different height were constructed and experimental investigation of heat transfer and flow with arrays of rectangular fins was conducted. Effect of velocity, attack angle, fin height and pitch ratio on local heat transfer coefficients is studied. In order to accomplish the experiment, 7 × 7 arrays of rectangular fins were attached on the heating surface and then placed in rectangular duct with different angle of attack to the free stream flow. Stream wise heat transfer coefficients were measured both at centerline and of 10 mm off line of heating surface by means of the thermocouples. T-type thermocouples and an infrared camera (TVS 8000) with a 160 × 120 point In-Sb sensor were used to measure the temperature and the detailed heat transfer from the endwall along with fin base.