In the UK, the Pavlik harness is generally the accepted treatment technique for the treatment of neonatal and infant pathological developmental dysplasia of the hip. In 2013, the success rate of the Pavlik harness became an outcome measure from the British Society of Children’s Orthopaedic Surgery for appraisal and revalidation with the GMC for paediatric orthopaedic surgery. The standard set requires an 80% success rate, with less than 20% requiring surgery. This study evaluated the outcomes of Pavlik harness treatment in neonates/infants with ‘pathological hips’ diagnosed by ultrasound imaging in a district general hospital setting. In a 10-year prospective observational longitudinal cohort study, modified Graf type III and IV hips (excluding those presenting with irreducible hip dislocation) were classified as pathological and splinted. A total of 2826 neonates/infants underwent ultrasound assessment in the paediatric orthopaedic ‘screening clinic’. Neonates and infants were referred as ‘at-risk’ or as clinically unstable by the Paediatric Department and by general practitioners. Thirty-one Graf type III and 95 Graf type IV hips were identified and treated with a Pavlik harness. One Graf type III (30/31=success rate 96.8%) and three clinically unstable Graf type IV hips progressed to irreducible hip dislocations (92/95=96.8%). The success rate of the Pavlik harness in Graf type III and IV dysplasia was 96.8%, with 3.2% requiring surgery because of progression of the condition, confirming acceptable results for this technique in a district general hospital setting.