Introduction: Peritoneal dialysis (PD) is increasingly used as a replacement method in end-stage chronic renal disease (ESRD), mainly due to its autonomy and quality of life benefits. However, peritonitis in PD, particularly Serratia marcescens peritonitis, can be a serious complication requiring catheter removal. Clinical case: We present the case of a 17-year-old adolescent who presented three episodes of peritonitis in PD characterized by dialysate fluid turbidity, abdominal pain, and vomiting without diarrhea in less than six months. Diagnostic workshop: The peritoneal fluid had a leukocyte count between 4,370 and 16,000 u/ul in each admission. The culture of the peritoneal fluid reported Serratia Marcescens in all three episodes. Treatment: For three weeks, empirical antibiotic treatment was with intraperitoneal ceftazidime (1 g/day, adjusted for antibiogram). After the last episode, the PD catheter was removed, and a second catheter was placed on the contralateral side. Outcome: Four days after catheter insertion, DPA was gradually restarted at low volume. After one year, the patient was free of peritonitis. Conclusions: Serratia marcescens is a gram-negative bacterium primarily responsible for recurrent peritonitis with a poor prognosis. Peritonitis caused by Serratia marcescens, like other Enterobacteriaceae, requires vigilant antibiotic management. Treatment tailored to the recommendations, despite in vitro sensitivity to third-generation cephalosporins, may improve the survival of the technique while preserving the catheter.