This article attempts to show that international literature on PCK research shows a great theoreticaldiversity that far from generating unanimity, seems to be generating tensions, and in some cases lackof clarity that leads to unsuccessful research results. From a brief analysis of this situation, an alternativeconceptual basis articulator on Pedagogical Content Knowledge (PCK) is proposed, and its operationis shown with concrete examples of content teaching for chemistry. These examples reinforcesome basic agreements in which the PCK can produce a general framework for curriculumdesign, development of teaching materials, initial training and continuing teacher education.