This paper analyzes the application of the theorem of corresponding states or the correspondence rule, as found in a number of advanced soil mechanics textbooks, and shows that it results in approximate solutions to limit-state problems. The limitations of the rule are made apparent by applying it to the determination of active pressures exerted on vertical retaining walls by cohesivefrictional backfills with inclined ground surfaces. A correct derivation of the correspondence rule is obtained for this case. An example is given that illustrates the inadequacy of this rule when boundary conditions are not properly accounted for in the analysis.Key words: theorem of corresponding states, active pressure, vertical retaining wall, inclined ground surface, cohesivefrictional backfill.