Although pyogenic abscess of the iliopsoas muscle is considered an uncommon condition, its incidence is on the increase. This abscess may be primary if it occurs without a causal factor; more frequently, it is secondary to gastrointestinal or genitourinary affections, or trauma. The main aetiological agents differ among primary (Staphylococcus aureus) and secondary (Escherichia coli, Klebsiella spp, Streptococcus spp, Bacteroides spp) abscess. We report the case of a 64-year-old man with iliopsoas abscess by S. aureus associated with spondylodiscitis in lumbar vertebrae (L4-L5). Our aim is to emphasize the successful treatment with exclusive intravenous antimicrobials, and highlight the role of control through imaging studies and laboratory tests.