We report a case of shoulder arthritis due to Haemophilus aphrophilus. The patient, a 56 year-old woman, was immunocompetent. She presented with a septic arthritis of the left shoulder without portal of entry. A synovial fluid sample was cultured and positive for a gram-negative bacillus after 8 days. It was identified as Haemophilus aphrophilus, in the HACCEK group, by PCR ARN 16S. We did not find any associated endocarditis. The patient recovered. As far as we know, this is only the 5th reported case of arthritis due to this microorganism.