We report the case of an adult who developed severe post-streptococcal reactive arthritis (PSRA) and poststreptococcal glomerulonephritis (PSGN) after a subclinical streptococcal infection. Antistreptococcal antibody titres, renal biopsy and the clinical course confirmed the diagnosis. Coincidence of PSRA and PSGN is rare in the adult population and the potential for misdiagnosis exists, particularly when prior streptococcal infection is not apparent. The clinical manifestations of poststreptococcal syndromes are highly variable, and the diagnosis of concomitant PSRA and PSGN should be considered when patients present with glomerulonephritis and inflammatory arthritis. Factors from both the host and the pathogen are probably important in determining disease expression in poststreptococcal syndromes.