Objective: This paper provides a detailed description of a method developed for purposes of linking records of individual patients, represented in diverse data sets, across time and geography. Design: The procedure for record linkage has three major components-data standardization, weight estimation, and matching. The proposed method was designed to incorporate a combination of exact and probabilistic matching techniques. Measurements: The procedure was validated using convergent, divergent, and criterion validity measures. Results: The output of the process achieved a sensitivity of 92 percent and a specificity that approached 100 percent. Conclusions: The procedure is a first step in addressing the current trend toward larger and more complex databases.