Despite significant progress to decrease its incidence, peritonitis remains the main source of morbidity and treatment failure in patients on continuous ambulatory peritoneal dialysis (CAPD). The majority of cases of peritonitis result from infection with aerobic gram-positive (Staphylococcus epidermidis and Staphylococcus aureus), or gram-negative organisms. Less common organisms that are also reported include anaerobic bacteria, fungi, and mycobacteria, which collectively account for less than 10% of isolates cultured. We report a case of peritoneal dialysis-associated peritonitis, and review the literature on peritonitis caused by Alcaligenes species. Alcaligenes xylosoxidans is a nonfermenting gram-negative rod and opportunistic pathogen that is motile with peritrichous flagella. The clinical features and microbiological data of our case, as well as the other previously reported cases of peritonitis caused by Alcaligenes species show no particular pattern of peritoneal dialysate cell count. However, the rate of recurrence of peritonitis is characteristically high. The cause of such a high rate of recurrence of peritonitis is probably a reflection of the predilection of Alcaligenes species to cause infection in the 'sicker' patients, and the almost universal resistance of this species to most antimicrobial agents. We, therefore, recommend that catheter removal be undertaken as early as the identification of the organism is made. Whether patients should be allowed to return to CAPD after recovery is a more difficult question. We suggest that a reevaluation of the patient's overall status be undertaken, including personal hygiene, exchange technique, presence of diabetes mellitus, malnutrition, and/or other factors that may render the patient more prone to infection with opportunistic pathogens.