The NASA Crustal Dynamics Project uses satellite laser ranging (SLR) and very long baseline interferometry (VLBI) data collected and analyzed by the Goddard Space Flight Center and the Jet Propulsion Laboratory for the measurement of geodynamic and geodetic parameters. An important parameter is the determination of the baseline length or intersite distance. Since October 1979, baselines determined from SLR data and VLBI data have been compared to help assess the accuracy of the baseline measurements from these independent techniques. Eight locations in the continental United States participated in the comparison: Westford, Massachusetts; Fort Davis, Texas; Platteville, Colorado; and Quincy, Owens Valley, Goldstone, Pasadena, and Monument Peak, California. Twenty-two baseline lengths between these locations, as determined by SLR, were differenced from the corresponding VLBI determinations. The rms scatter about zero for the length differences is 5.2 cm with a mean of 1.0¿1.1 cm, and there is no apparent scale factor between these two distance determinations. For this result, the Monument Peak-Quincy baseline has been adjusted for tectonic plate motion by using the SLR-determined baseline rate. For the eight other baselines crossing a plate boundary, tectonic motion was not modeled. If a model for this motion based upon baseline changes derived from strain rates is applied, the rms scatter about zero for the 22 differences becomes 7.2 cm, with a mean of 1.0¿1.1 cm. The above results are within the combined error budgets of the SLR and VLBI baseline length determinations.