The injection and temperature dependence of the spontaneous emission quantum efficiency of molecular beam epitaxy grown InGaAs/GaAs quantum wells is determined using excitation dependent photoluminescence (PL) measurements. The PL measurements were performed at temperatures from 50 to 300 K using a HeNe pump laser with powers ranging from 0.6 to 35 mW. The quantum efficiency is inferred from the power law predicted by the rate equations that links pump power and integrated PL signal. The peak spontaneous emission quantum efficiency of molecular beam epitaxy (MBE) grown InGaAs/GaAs triple quantum wells is determined to be 0.941 at 300K with an overall best value of 0.992 at 100 K.