The objective of this study was to compare the efficacy of portable blood glucose measurement method in relation to the laboratory reference method, using central venous and capillary blood samples from 20 cats. The value obtained by the laboratory method using central venous blood sample was considered as the standard reference value. Other two values were obtained from the portable blood glucose meter, in which a sample from the same central venous blood and another one sample from capillary blood were used. For the 20 cats, the blood glucose results obtained by the laboratory method had an average of 80mg/dL; and the results found by the glucometer had an average of 84.1mg/dL with central venous blood and of 73.1mg/dL with capillary blood. The glycemic averages obtained by the glucometer with both blood samples compared to that achieved by the laboratory method resulted in variations below the maximum established (20%) by associations that regulate portable glucometers and by the organization for standardization, as well as the variation between the glycemic averages obtained by the glucometer using different blood samples. In the comparative analysis, there was no significant difference between the methods (p<0.05). In conclusion, the portable glucometer is effective in measuring blood glucose in cats, both from central venous blood and capillary blood samples.