Ketosis, defined as blood beta-hydroxybutyrate (BHBA) concentrations greater than 1,400 umol/1, is an important problem in dairy herds. Prompt and accurate detection of ketosis may lessen its negative effects on milk yield and reproduction, and may help prevent subsequent displaced abomasum. Cowside tests are necessary for prompt diagnosis and treatment of ketosis; however, existing cowside urine or milk ketone tests are limited by their relatively low sensitivity (about 80%) compared to blood BHBA (the gold standard test for ketosis). Cowside blood glucose tests have not been commonly used but could be useful in helping clinicians determine if glucose treatments are indicated for early lactation cows with an unknown diagnosis or that have already been treated for ketosis. The objectives of this study were to evaluate the correlation of BHBA and glucose results from the hand-held meter with laboratory analysis results, and to evaluate the sensitivity and specificity of the hand-held meter for determining BHBA and glucose concentrations above established cut-points.