In a randomised, controlled, single-blind trial, we examined the effect of a pre-emptive alveolar recruitment strategy on arterial oxygenation during subsequent pneumoperitoneum. After intubation, 50 patients were randomly allocated to receive either tidal volume 10 ml/kg with no positive end-expiratory pressure (group C) or alveolar recruitment strategy of 10 manual breaths with peak inspiratory pressure of 40 cmH2O plus positive end-expiratory pressure of 15 cmH2O before gas insufflation (group P). During pneumoperitoneum, group P was ventilated with the same setting as group C (FiO2,= 0.35, tidal volume 10 ml/kg). PaO2, measured during peumoperitoneum was higher in group P than in group C (166 +/- 32 mmHg vs 145 +/- 34 mmHg at 15 minutes, P = 0.028, 155 +/- 30 mmHg vs 136 +/- 32 mmHg at 30 minutes, P = 0.035). Alveolar-arterial oxygen gradient in group P increased less after gas insufflation (13 +/- 9 to 60 +/- 34 mmHg vs 10 +/- 9 to 37 +/- 31 mmHg, P = 0.013). We conclude that the alveolar recruitment strategy we applied before insufflation of the peritoneal cavity may improve oxygenation during laparoscopic hysterectomy