Experiments are carried out in a specially designed cell to study the onset and propagation of dryout point on a chemically machined microgrooved silicon surface with pentane as the coolant liquid. The axial temperature distribution is accurately measured as a function of the heat input and inclination of the substrate. The comparison between the dry (without liquid) and wet (with liquid) temperature profiles is used to locate the dryout point. The axial flow of an evaporating thin liquid film through a V-shaped microgroove with an appreciable inclination angle and varying evaporative heat flux is theoretically investigated. The nonlinear governing equations are solved numerically to predict the onset, location and propagation of the dryout point. The predictions from the theoretical analysis are successfully compared with the experimental results.