Actinomycosis is an uncommon entity caused by an anaerobic bacterium, Actinomyces species, most often Actinomyces israelii. We present a patient who suffered from progressive lumbar pain and high fever. Actinomycosis infection was diagnosed after extensive radiological and pathological evaluation. Treatment with i.v. ampicillin was started, followed by oral antibiotics for one year. This paper gives an overview of the different clinical presentations of actinomycosis infection, with special attention to the skeletal involvement. We also discuss diagnosis and treatment. The clinical picture can mimic several other conditions, such as lymphomas. Delay in diagnosis and treatment can significantly worsen the condition of the patient.