The protective effect on peritoneum of L-carnitine and its lower alkanoylderivatives, both in the form of inner or pharmaceutically acceptable salts isdisclosed. Concentrations of carnitine from about 0.02 to 0.5% w/v aresuitable for preparing a solution for peritoneal dialysis having higherbiocompatibility and protecting peritoneum from toxic effects of continuoususe of solutions for peritoneal dialysis, in particular ones containingglucose as osmotic agent. A particularly preferred embodiment is a solutionfor peritoneal dialysis containing carnitine, glucose and xylitol.