Heart failure with congestion is the most common cause of patient hospitalization which could result in worsening of renal function (WRF) and or acute kidney injury. Diuretic is widely used in congestion, but the increase of administration dosage will worsen the kidney function. Meanwhile, tolvaptan is known to have beneficial effects on congestion patients. Therefore, a systematic review was conducted to understand the effect of tolvaptan in renal function in heart failure patients using diuretics. This systematic review obtained data from Pubmed and Scopus from the last five years. Tolvaptan, diuretic, renal function, and heart failure were used as the keyword in the search, and used PRISMA statement as the method. Finally, the data was analyzed to figure out the effect of tolvaptan in renal function. Three RCT studies from 78 studies had assessed. The main result from all studies showed that the incidence of WRF was significantly lower in the Tolvaptan (TLV) group than non-TLV ones (p < 0.05). Next, two studies described that non-TLV groups had higher serum creatinine levels than TLV groups (p<0.05). Finally, the decrease in eGFR was significantly larger in non-TLV groups (p<0.05). These results could happen as tolvaptan is a competitive oral vasopressin V2-receptor antagonist. This drug inhibits vasopressin-mediated water reabsorption in the renal collecting ducts and promotes an increase in free water clearance. In addition, tolvaptan acts as a pure aquaretic and can also increase renal blood flow and decrease renal vascular resistance without activating the RAAS, which can improve GFR. Tolvaptan has been proven to have a renoprotective effect. However, further clinical trials with larger populations and better methods are needed to completely understand the effect of tolvaptan in renal function in heart failure patients using diuretics.