All malignant cells appear to have increased needs for glucose in vitro as well as in vivo. The enhanced glucose uptake is mediated through transporters (Gluts), whose action and expression are regulated by oncogenes and growth factors. Cyclin D1 is a nuclear protein that plays an important role in regulating the cell cycle by promoting entry of cells from the G1 to S phase. Increased expression of Glut1 glucose transporter and cyclin D1 have been reported in several neoplasms. In the present study we examined the expression of Glut1 and cyclin D1 in breast carcinomas with negative lymph nodes. We studied 78 infiltrating ductal carcinomas (25 grade 1, 36 grade 2, and 17 grade 3) with negative lymph nodes. Glut1 was expressed in 28% of grade 1, 63.8% of grade 2 and 58.7% of grade 3 carcinomas. Nuclear expression of cyclin D1 was detected in 32% of grade 1, 44.4% of grade 2, and 41.2% of grade 3 carcinomas. From our study it appears that in breast carcinomas with negative lymph nodes Glut1 expression is better correlated to the grade of the neoplasm than cyclin D1.