The second law analysis of a gravity-driven liquid having temperature-dependent viscosity and flowing along an inclined heated plate was studied. The computational fluid dynamics (CFD) package FLUENT was used to obtain the velocity and temperature gradients, and the results were used to determine the entropy generation rate. Different cases of inclination angle and dimensionless parameters were investigated. There is significant difference in the entropy generation rate magnitude in comparison to the entropy generation for constant physical properties case. The entropy generation rate has its maximum value near the plate surface and decreases sharply towards the free surface. It also decreases in the longitudinal axial direction due to the decrease in the temperature difference between the plate and film temperate towards the downstream. Changing the inclination angle has no significant effect in the entropy generation rate except near the plate surface.