A 77-year-old woman had a history of mantle cell lymphoma, splenechtomy and rituximab-treatment. For six months she had fever, night sweats and weight loss. Thorough investigations did not reveal the cause of the fever, and empiric antibiotics had no effect. Eventually she developed an erythema nodosum-like rash on both legs. A biopsy was sent for 16S rRNA PCR, which was positive for Candidatus Neoehrlichia mikurensis. She was treated with doxycycline with resolution of all symptoms. This is the first case report of neoehrlichiosis in Denmark, and the first case diagnosed on a skin biopsy.