We described the clinical symptoms and signs of 11 cases of polyenthesitis, confirmed by the presence of inflammation in biopsies and increased activity in scintigraphy. All cases are negative for HLA-B27, and there is no presence of systemic inflammatory reaction, radiographic sacroiliitis, or chronic arthritis. The enthesitis is not ossifying and follows a rather benign clinical course. In one case, herpes virus-like particles were detected in the fibroblast debris of the tissue removed from Achilles tendon insertion. This fact suggests that polyenthesitis may be a clinical manifestation due to a reaction to an infectious agent.