Experiments have been performed to investigate mixed convection heat transferin the thermal and hydrodynamic entrance region of a uniformly heated inclined tube.The effects of surface heat flux, Reynolds number, the direction of main flow relativeto secondary flow (opposing flow), and angle of tube inclination on the temperaturedistribution and local Nusselt number along tube were studied. The study covered Reynolds number range (450≤ Re ≤2008), and heat flux range (95 ≤ q ≤898) W/mRayligt number from 1.1132105 to 3.6982105 and angle of inclination α=0°(Horizontal), α=30°, α=60° (Inclined), α=90° (Vertical).Results show that the heattransfer process improve whenever move angle of inclination from vertical position tohorizontal position . The experimental data were correlated for Nu as a function ofRam &Remm for each angle of inclination and then superimposed the angle of inclination to give a general equation of average Nusselt number at any α in opposing flow. 2,