A 39-year-old man presented pronounced asthenia and diffuse myalgias 8 months after a vaccination against the tetanus toxoid. Muscle biopsy disclosed infiltration of the perimysium and endomysium by densely packed, PAS-positive macrophages. Tropheryma whippelii detection in blood and faeces allowed the initial assumption of atypical Whipple's disease with isolated muscle involvement. However, the histological detection of aluminium-containing macrophages by means of Morin stain immunofluorescence established the diagnosis of macrophagic myofascitis in an obviously asymptomatic T. whippelii carrier.