ABSTRACT The differences found in the relativistic and nonrelativistic methods used in the literature to account for short range nuclear correlations in the decay of Λ hypernuclei are analyzed. By means of a schematic microscopic model for the origin of correlations, the appropriate method to include them in nuclear processes is derived and is found to be the same one used in the nonrelativistic approach. The differences do not stem from relativistic effects but from the improper implementation of the correlations in the relativistic approach, which leads to several pathologies as shown in the paper. General formulas are given to evaluate the nonmesonic decay width of finite hypernuclei and results are obtained for 5 Λ He and 12 Λ C .