A relatively inexpensive semi-automated enzymatic procedure is described for the determination of total glycerol with an Auto Analyzer. Free glycerol is determined without saponification in a deproteinized supernatant. 2. The dilution of triglyceride samples during preparation is such that the samples during preparation is such that the samples can be quantified directly from the free glycerol standards by multiplying by 100. 3. A pyruvate kiluent solution is used in the triglyceride sample preparation to increase the precision by improving the accuracy in determining blank optical densities. 4. The end-point reaction is complete in eight minutes, and the assay is linear up to 6 mg% free glycerol or 600 mg% triglycerides. The within-run and between-run coefficients of variation were both 1.5% for the glycerol assay, and 1.0% and 4.3% for the triglyceride assay. The mean recovery of added glycerol was 100.7% and 102.3% for the glycerol and triglyceride assays respectively.