The presented paper addresses the question of the NPV-compatibility of the Overall Rates of Return (ORRs), and analyses two project ranking procedures that were advocated in the recent contribution “Overall Rates of Return: Investment Basis, Reinvestment Rates and Time Horizons” by D.M. Shull(The Engineering Economist, Vol.39, No.2, Winter 1994, pp. 139-163). The paper indicates that the current definitions of the ORRs are not fully NPV-compatible, and it provides a generalized, NPV-compatible ORR definition. The paper further shows, using numerical examples, that the two project ranking procedures adopted by Shull are conceptually inadequate. It presents the correct approach to project-ranking, and proves that this approach can be used in conjunction with any NPV-compatible profitability criterion. Also, the paper addresses and rectifies some inaccurate statements and formulas in Shull's contribution. Finally, it is noted that Shull's Scale-Adjusted Return Method was, in fact, introduced nineteen years ago by P.J. Athanasopoulos (“A Note on the Modified Internal Rate Of Return and Investment Criterion, ”The Engineering Economist, Vol.23, No.2, Winter 1978, pp. 131-133).