This paper presents a performance analysis of a concurrent file reorganization algorithm. W e examine the effect of ( i ) buffer size, (ii) degree of reorganization and (iii) write probability of transactions on system throughput. The problem of $le reorganization which we consider involves altering the placement of records on pages of a secondary storage device. In addition, we want this reorganization to be done in-place, i.e., using the file's original storage space for the newly reorganized file. Our approach is also appropriate for a non in-place reorganimtion as well The motivation for such a physical change, i.e., record clustering, is to improve the database system's performance, i.e., minimizing the number of page accesses made in answering a set of queries. In this work we show through simulation that our algorithm, when run concurrently with user transactions, provides an acceptable level of overall database system performance.