We have previously shown that the addition of Granulocyte-macrophage colony-stimulating factor (GM-CSF) during in vitro oocyte maturation (IVM) can increase mitochondrial activity and reduce the level of reactive oxygen species (ROS) in cumulus-oocyte complexes (COCs). The present study was undertaken to determine if the addition of GM-CSF during IVM increases glucose uptake in COCs. C57Bl6 x CBA F1 female mice aged 21-23 days were injected IP with 0.1 ml of eCG and COCs aspirated from large antral follicles 46-48 h post-injection. COCs were placed in HEPES alpha-MEM media supplemented with 0 and 10 ng/ml of GM-CSF with 0.3mM of 6 NBDG. COCs were incubated for 0, 15, 30, 60 and 90 mins at 37 C in 6%CO2, 5%O2, and 89% N2. Following incubations COCs were washed in G-MOPS (Vitrolife) and then loaded in groups of five onto glass slides for imaging. Glucose uptake in COCs was measured at excitation and emission wavelength of 488nm using The Cell Voyager CV1000 Confocal Scanner (Yokogawa) with Z-stack imaging and analysed using Fiji Image J software. The experiment was replicated three times with 25-28 oocytes per group. Data were normalised with logarithmic transformation and assessed using univariate general linear models with Bonferroni post hoc test using IBM SPSS. Adding GM-CSF during IVM increased glucose uptake at 15 minutes by 9.26 % (P<0.001) compared with control. While at 30 and 60 minutes there was an increase in uptake in the control group by 3.1% (P < 0.05) and 4.0% (P<0.01) respectively. No effect was observed at 90 minutes in both groups suggesting uptake had reached maximum levels. In conclusion, we have shown that adding GM-CSF during IVM increases the glucose uptake rate, which may contribute to the increase in mitochondrial activity and reduction in ROS levels reported previously.