A numerical simulation is used to investigate the effect of adding secondary hole branched out from a compound angle injection hole. The use of secondary holes with compound angle film cooling is considered as a novel concept of compound angle film cooling. The used orientation angle is 30°. The diameter of the secondary hole is half of the main diameter (compound angle injection hole diameter). The studied cases are considered at blowing ratios of 0.5, 0.75, 1.0, 1.5, 2.0, and 2.5. The study was carried out using the realizable k-ε model. The presence of the secondary hole improves the film cooling at all studied blowing ratios except at M = 0.5 due to the weakness of the coolant flow through the main hole. The flow through the secondary hole tries to damp the vortex coming out from the main hole. The optimum blowing ratio is at M = 0.75–1.0. The enhancement in the overall film cooling effectiveness at M = 1 is 0.12 as compared to the compound angle injection hole case by about 83%.