Optical spectra were studied for several sets of InGaN/GaN multiple quantum well samples, grown with MOCVD at different conditions. One set of samples was prepared with the InGaN layers grown at 700 C, and the GaN barriers at 1000 C, another set was grown under conditions 780 C and 1000 C, respectively. A third set of samples was grown at 820 C for both barrier and well material. These sets of samples show fairly different spectral properties, the two former have rather broad single peak spectra, while the latter shows multiple peak spectra. The piezoelectric field is important in governing the recombination properties, as is also the localization. potentials, in particular for the lower InGaN growth temperatures. For the 820 C samples we suspect that a surface roughness affects the center QWs causing additional PL transitions.