Obstructive Sleep Apnoea Hypopnea Syndrome (OSAHS) is a disorder characterised by events of partial or complete cessation in breathing during sleep and an excessive daytime somnolence. The pathophysiology of the condition is multifactorial. Obesity is one of the major risk factors for OSAHS. The relationship between both is not yet fully understood, but it is well evidenced that losing weight can improve OSAHS symptoms. Continuous Positive Airway Pressure (CPAP) is a first line of treatment in moderate to severe OSAHS, however, its effect on weight loss remains unclear. The aim of this service evaluation was to investigate if there is any relationship between compliance with CPAP and weight change in order to assess the need for weight loss clinic. To achieve the aim, we performed a retrospective analysis of data sets of 77 overweight and obese OSAHS patients who were treated with CPAP for a minimum 5 years was performed. Correlation between CPAP compliance and weight loss was assessed with a Pearsons correlation. 38/77 participant’s weight increased from baseline to visit 5, 36/77 experienced weight loss and 3 subjects remained weight neutral. 50/77 patient’s data sets demonstrated compliance greater than 95% across 5 years, a further 27 subjects had compliance less than 95%. Assessment for a correlation between compliance and percentage change in body weight after 5 years of treatment demonstrated no correlation r = 0.045 (p 0.69).This report backs up similar findings that CPAP compliance alone does not promote weight change, a multidisciplinary approach to weight loss management may improve long term patient outcomes.