AbstractMyositis is an infectious disease that affects skeletal muscle and may appear as a diffuse inflammation or a rapidly progressive myonecrotic process that often results in abscess development. It is most common in thigh muscles. Staphylococcus aureus is the most common microorganism, accounting for 90% of cases. Pyomyositis diagnosis can be challenging due to neglect of initial symptoms, and usually presents with fever and muscle pain. Standard antibiotic treatment is the mainstay. However, it can be effectively treated with homoeopathic medicines by considering local pathology and other individualised characteristics. A 58-year-old male patient consulted with a non-healing abscess of myositis with multi-morbid conditions. Initially treated in outpatient department without any positive change, he was later admitted to inpatient department of National Homoeopathy Research Institute in Mental Health, Kottayam, and treated for 45 days. Merc. sol. 0/1 was given as the first prescription and repeated as required in the follow-up visits. Syphilinum 200 was given as an intercurrent remedy to address predominant syphilitic miasm. Abscess of myositis was cured, and diabetes and hypertension were under control. There was an improvement in sensorineural deafness in both ears, and his craving for alcohol was also reduced. The changes in outcome and causal attribution were assessed using the Modified Naranjo Criteria. The score was +9, close to the maximum (13), showing positive relationship between homoeopathic intervention and the outcome. This case proves the positive role of homoeopathic medicines intervention in treating non-healing abscess of myositis associated with multimorbidities.