A quasi‐experimental, repeated‐measures cross‐over design study on the effect of body position on oxygenation (SaO2) blood pressure, respiration and pulse in patients with unilateral lung pathology was conducted Previous research strongly suggests that positioning with the healthy (unaffected) lung in the dependent lateral (down) position is related to improved oxygenation, but knowledge about whether this effect is maintained over time is lacking The purpose of this investigation was to determine (1) Is positioning with the unaffected lung in the dependent lateral position related to increased arterial blood saturation levels and decreased blood pressure, pulse and respiration? (2) What is the relationship between the dependent variables — oxygenation saturation levels, blood pressure, pulse and respiration — and the independent variables — body position and time in the position? Thirty‐nine patients with unilateral lung pathology were positioned on their sides with the unaffected lung down, on their sides with the affected lung down, and also in semi‐Fowler's position Arterial (SaO2) blood saturation and vital signs were measured at baseline 0, 15 and 30 minutes There was no statistically significant relationship between oxygenation level or systolic blood pressure Diastolic blood pressure, respiration and pulse did vary significant