To determine the clinical and analytical accuracy of a new veterinary-calibrated portable blood glucose monitor (PBGM) compared to a reference laboratory analyzer. Client-owned dogs (n = 77) and cats (n = 64). Peripheral and paired capillary whole-blood glucose concentrations measured via PBGM were compared to plasma glucose concentrations measured via a Cobas c501 reference analyzer (Roche). Analytical accuracy was evaluated with the Spearman rank correlation coefficient, Bland-Altman difference plot analysis, and Deming regression. Clinical accuracy was evaluated with Parkes error grid analysis. Paired peripheral and capillary blood samples were compared with the Wilcoxon matched-pairs signed-rank test. There was a high correlation between PBGM and reference analyzer readings in dogs and cats. Human quality assurance standards (International Organization for Standardization 15197:2013 guidelines) for analytical accuracy were met for 95% of feline peripheral blood samples and 89% of canine samples. Similar veterinary standards (American Society of Veterinary Clinical Pathology guidelines) were met for 89% of canine and 92% of feline peripheral blood glucose measurements. Error grid analysis showed that all peripheral canine and 97% of feline measurements were clinically accurate (zone A). Any altered clinical decision for the remaining feline measurements was expected to minimally impact outcome (zone B). No significant difference was found between peripheral and capillary blood glucose measurements in either species. The PBGM produced clinically accurate results and is suitable for use in veterinary and home settings to measure blood glucose.