This paper reports on the optimization of the growth of visible-wavelength vertical-cavity surface-emitting laser (VCSEL) diodes by metalorganic vapour-phase epitaxy (MOVPE). The VCSEL structure has an GaInP/AlGaInP quantum well active zone (AZ) sandwiched between AlGaAs/AlAs distributed Bragg reflectors (DBRs). We present results on the optimization of the DBR reflectivity and the electrical resistance of the p-DBR and discuss the switching sequence at the AZ to p-DBR interface which is critical due to the change of the group V component. Using these optimized parameters 640-655 nm emitting VCSELs could be demonstrated, with a minimum threshold current density of 2.8 kA/cm(2) at 654 nm.