High quality pavement profile data are important to both the LTPP research, and highway agency pavement management systems. This report documents a study conducted to evaluate the quality and variability of the longitudinal profile data in the Long Term Pavement Performance (LTPP) database. The study focuses on LTPP profiles collected between June 1989 and October 1997. These profiles were visually reviewed for saturation spikes, lost lock, shifted starts, wrong location, out of study and other equipment-and-operator-related problems. Noted problems are identified in the report. Repair, replacement, or deletion of these files was completed in conjunction with this study. Remaining or replaced good profile data were used for analysis of variability