m Analytical exact expressions are obtained for matrix elements of the modified Poschl-Teller oscillator over different operators including powers of the hyperbolic functions sinh( a x ) , cosh(a x ) , and tanh( a x) and the differential operators d / d x and d 2 / d x 2 . These expressions are derived using explicitly the Poschl-Teller eigenfunctions. In addition, several recursion relations connecting different Poschl-Teller matrix elements are obtained using the factorization and hypervirial techniques. It is shown that these relations can be used to make easier the computation of the matrix elements. 0 1996 fohn Wiley & Sons, Inc.Let us consider the evaluation of the matrix elements of powers of sirMax), cosh(ax), and 44 VOL. 57, NO. 1