Employing the general principles of classification of SU 3 states, we have found 285 quantum number isomers (QNI), i.e. nuclei for which there are two possible SU 3 quantum number sets, characterized by the maximal eigenvalue of the SU 3 group Casimir operator, at the minimal value N min 0 for the quantum number N 0 of the group U 3(A−1) symmetric representation, allowed by the Pauli principle. 41 of these QNI can be attributed to the non-excited, ground SU 3 configurations of realistic nuclei. Two examples of QNI: 28 Si and 60 Zn, have been studied in detail in the framework of the strictly restricted dynamics model (SRDM).