Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents with non-bilious vomiting and failure to thrive secondary to gastric outlet obstruction. In the UK, management is by fluid resuscitation followed by pyloromyotomy. Incomplete myotomy complicates 0.3% of cases necessitating further surgery and exposing the patient to further risk. Medical management of IHPS with antimuscarinics to promote pyloric relaxation is a well-described treatment modality that is used as first-line therapy in some countries. The use of this technique is limited by the need for extended hospital admission with parenteral nutrition administration. We describe a case of IHPS complicated by incomplete pyloromyotomy and subsequently managed successfully by atropine sulphate therapy.