We present a study of the growth, morphology and optical properties of Al(x)Ga(1-x-y)In(y)As quantum dots (QDs) for a wide range of Al and In concentrations (0≤x≤0.34 and 0.43≤y≤0.60). Short emission wavelengths between 660 and 940 nm and QD surface densities up to 1.1 × 10(11) cm(-2) have been achieved. Our results show that by varying both the Al concentration and the In concentration an independent adjustment of strain and QD band gap is possible. This additional degree of freedom can be employed for tailoring AlGaInAs QDs with the desired emission wavelength, surface density and average size. AlGaInAs QDs thus offer new possibilities for future QD device design.