A prospective observational study examing the incidence, predisposing factors and microbiological aspects of peritonitis complicating acute intermittent peritoneal dialysis (IPD) was performed in Hospital Universiti Sains Malaysia, a referral hospital situated in Northeast Malaysia. Over a 7- month period, a total of 126 acute IPD treatments were included involving 69 patients. The majority of patients suffered from chronic or end stage renal failure (92.7%) and nearly half (47.8%) have underlying diabetes mellitus. Peritonitis occured in 25 treatment sessions giving a frequency of 19.8% of procedures performed. The mean interval between starting dialysis and the first sign of peritonitis was 3.5 days, with 12% of peritonitis occuring before day 3 of treatment. Frequent catheter manipulation and/or leakages were identified as significant predisposing factors for peritonitis and the risk of peritonitis was increased with longer duration of IPD. Gram-negative infections were seen twice more commonly than gram-positive infections. We recommend the use of cloxacillin in combination with either an aminoglycoside or a cephalosporin as empirical antibiotic coverage until culture reports are available.