The revised quantitative insulin sensitivity check index (RQUICKI) has been utilized to evaluate insulin resistance in dairy cows; however, discrepancies between RQUICKI and direct measurements of insulin sensitivity are documented. Our objective was to compare RQUICKI with glucose and insulin tolerance in non-fasted peripartal dairy cows. Multiparous Holstein cows were grouped by BCS at d −28 prepartum: lean (BCS 2.91 ± 0.13; n = 7) or overweight (OVER; BCS 4.03 ± 0.21; n = 7). Diets were formulated to meet nutrient requirements. An intravenous insulin challenge (0.1 IU/kg BW; ITT) was performed on d −26 and −13, relative to expected calving, and 5 DIM. An intravenous glucose challenge (0.3 g/kg BW; GTT) was performed 24 h post- ITT . Blood and milk were collected routinely. Data were analyzed using a mixed model with repeated measures (fixed effects of BCS and day). Effects are presented as changes relative to lean cows, unless described otherwise. OVER had lower DMI, and lost more BCS and BW postpartum (P < 0.05). Adiposity had no effect on milk yield, milk protein yield, and SCC; however, milk fat yield was greater in OVER (P < 0.05). OVER had increased plasma NEFA and BHBA (P < 0.05). Prepartum plasma insulin levels were higher in OVER (P < 0.05). Although plasma glucose levels declined with time (P < 0.01), BCS did not modify plasma glucose. RQUICKI values were lower for OVER pre- and postpartum (P < 0.05). Postpartum cows had lower insulin-stimulated glucose disposal, relative to prepartum cows (P < 0.01). Following insulin-stimulated glucose disappearance, return to basal glucose in OVER was delayed by 60 min (P < 0.05). BCS had no effects on GTT; however, post-glucose challenge area under the curve (AUC) for 180 min and clearance rate (%/min) for the first 30 min were lower for postpartum cows, relative to prepartum cows (P < 0.05). Before and after calving, OVER experienced greater glucose-stimulated reductions in NEFA and AUC for 180 min following glucose challenge (P < 0.05). Observed inconsistencies between RQUICKI and tolerance testing may be due to direct measurements in the fed state.