The effect of oxygen pressure and laser pulse duration on the production of thin films of La0.7Sr0.3CoO3-delta (LSC) and La0.7Sr0.3Co0.2Fe0.8O3-delta (LSCF) by laser ablation has been investigated. Evidence of reduction and phase separation of the target surfaces was found by X-ray diffraction. Ablation of LSC, at low oxygen partial pressures and with an excimer laser, led to the production of poor quality films, compared with the LSCF. This is attributed to the greater stability of LSCF in terms of low oxygen pressures.