The traditional and accelerated titration (AT) designs are two frequently utilized Phase I clinical trial designs. Although each design has theoretical advantages and disadvantages, a summary of the practical application of these theories has not been reported. We report our center's experience in evaluating novel agents using both types of Phase I trial designs over a 13-year period. Results from nine Phase I clinical trials of multiple cytotoxic agents conducted at Wayne State University/Karmanos Cancer Institute in Detroit, MI, and published from 1995-2005 were analyzed for this report. Parameters analyzed included the number of patients, the number of dose levels, the total time to completion of the study, and adverse events. The mean number of patients treated on four Phase I trials using the traditional Phase I trial design was 34 compared to a mean of 23.8 patients treated on five Phase I trials using the AT schema. The mean number of dose levels in patients treated using the traditional Phase I trial design was 8.8 (range 7-11) compared to a mean of 10.6 (range 7-15) dose levels using the AT design. The mean length of study time (25-26 months) was similar in both trial designs. The theoretical advantages and disadvantages of both Phase I trial designs did not readily emerge in their actual application in clinical trials conducted at our institution.