We used a digital display value, a recorded pressure curve, and manometric measurements to determine CVP in 35ICU patients who had either a central venous line or a pulmonary artery catheter. CVP was measured by each method up to five times per patient, for a total of 107 data sets. Display values compared well to those from the recorded pressure curve. Manometric measurements, however, poorly matched electronically determined values. Factors influencing these results are discussed.