Fat accumulation in adipose tissues is a risk factor for the development of human cancers. However, there are no studies describing the fat accumulation in adipose tissue or its distribution in human endometrial cancer. We first examined fat accumulation in adipose tissues separately on CT images of 122 patients with endometrial cancer, and investigated the correlation of these findings with various histological types of endometrial cancers. Fat accumulation in adipose tissues [subcutaneous fat area (SFA) and/or visceral fat areas (VFA)] was strongly correlated with the group of obesity-related biological parameters (weight, body mass index (BMI), waist and body surface area (BSA)) in endometrial cancer. The incidence of type I endometrial cancer was more closely correlated with an increase in obesity-related parameters such as weight (p=0.011), BMI (p=0.006), waist circumference (p=0.038), BSA (p=0.016), SFA (p=0.005), total fat area (TFA) (p=0.006) and total cholesterol (T.Cho) (P=0.010) than type II endometrial cancer. In particular, the SFA was most strongly correlated with obesity-related biological parameters of type I endometrial cancer. The present findings indicate that type I endometrial cancer has a statistically significant increase in obesity-related biological parameters than type II endometrial cancer. We propose that the subcutaneous fat accumulation in adipose tissue is a strong risk factor for developing type I endometrial cancer.