Introduction <p>The incidence of MASLD is rapidly increasing while the accuracy of noninvasive tests for MASLD remains limited. Indocyanine green clearance is a dynamic liver function test established for the evaluation of liver disease but is limited by the major influence of systemic circulation. We aimed to assess the role of Indocyanine green clearance in the evaluation of MASLD, together with cardiac function measurements.</p> Methods <p>We conducted a prospective controlled study of 77 patients who underwent metabolic and bariatric surgery (MBS) and 25 controls who underwent elective cholecystectomy. Indocyanine green clearance was measured and interpreted as plasma disappearance rate (PDR) and residual dose at 15 min (R15). Wedge liver biopsies were obtained during MBS and assessed using the Kleiner classification. In the observed group cardiac output and cardiac index were measured and used to evaluate the influence of cardiac function on liver function monitoring.</p> Results <p>Indocyanine green clearance was significantly lower in the observed patients compared to controls (<i>p</i> &lt; 0.05). PDR was significantly associated with a pathological histological score (<i>p</i> = 0.03). Cardiac output and cardiac index were independently associated with R15 (<i>p</i> &lt; 0.01). PDR adjusted for cardiac output and cardiac index significantly corelated with liver fibrosis, revealing a relationship not evident in unadjusted measurements.</p> Conclusions <p>Indocyanine green clearance reflects MASLD severity in MBS patients. Its diagnostic value is further enhanced by adjusting for cardiac function. This novel combined approach may improve noninvasive assessment of MASLD and support treatment individualization in patients preparing for MBS.</p>