摘要AIM: To establish a quantitative method to measure the amount of lipids. METHODS: The livers of 53 male Wistar rats (225g) with different degrees of hepatic steatosis were studied. This model of hepatic steatosis was based on a high carbohydrate, fat-free modified diet. Biopsies were classified into four grades depending on fat accumulation, using the Kleiner and Brunt classification. Total fat was studied by the Soxtec method (Soxtec. 2050 Auto Fat Extraction System), and agreement between both assays was assessed by calculating the κ coefficient. RESULTS: According to the histological classification, 38% of rats presented grade 0, 21% grade 1, 22% grade 2 and 20% grade 3. The amount of fat per 100 g tissue was 2.60±0.64 g for grade 0, 3.87±1.59 g for grade 1, 5.82±1.37 g for grade 2 and 8.68 ±2.30 g for grade 3. Statistically significant differences were found between the mean values for each of the histological grades (P<0.05). The correlation for the quantification of fat in the liver between both assays was moderate (κ=0.60). CONCLUSION: The biochemical quantification of fat in liver tissue by the Soxtec method was correlated with the histological classification, although the agreement between the two tests was only moderate.