Congestive heart failure (CHF) refractory to pharmacological therapy is a growing medical problem. Renal sodium and water retention remains a key event in the pathogenesis of the disease progression and episodes of severe cardiac decompensation, being also the leading cause of high hospitalization rates and an important risk factor for worsening kidney function and chronic kidney disease (CKD). The two conditions: CHF and CKD form a vicious circle, with a tremendous escalation of complications and mortality. In this clinical situation, peritoneal ultrafiltration (PUF) may be a reasonable choice for long-term treatment of selected patients with end-stage CHF, especially for those with contradictions to heart transplantation. Several observational studies have demonstrated its efficacy and safety in this population. Fluid and sodium removal via peritoneal cavity resulted in significant plasma volume reduction, normalization of serum sodium and restoration of diuretic responsiveness, as well as an improvement in New York Heart Association functional class, reduction of hospitalization and readmission rates. The complications are typical for peritoneal dialysis (catheter exit site infections, peritonitis and fluid leaks) but they are much more rare with 1 instead of 4 exchanges per day,and it seems that at least in case of PUF with 1-2 peritoneal exchanges a day, the benefits of the therapy outweigh the risks. However, as the studied groups were small, larger multicenter randomized trials are necessary to develop precise recommendations regarding clinical aspects of PUF in severe CHF and indications for its use.