Based on long-term observations the authors submit a categorization of primary (hereditary and solitary) articular chondrocalcinosis into three different sub-populations. Attention is drawn to the fact that the extent of the qualitative disorder of the articular cartilage, obviously conditioned genetically, is linked with the age factor and determines the quantitative differences of pyrophosphate arthropathy in primary chondrocalcinosis. In young age, as a rule in the third decade, severe polyarticular condrocalcinosis (first sub-population) develops which causes relatively soon invalidity, in middle age (5th and 6th decade) milder condrocalcinosis develops (second sub-population) which combines with extraarticular, tendinous and tissue calcifacations, and finally in advanced age oligoarticular chondrocalcinosis develops (third sub-population) which is usually associated with ankylosing hyperostosis of the spine. Articular chondrocalcinosis (CCA) which we described by this term as a special metabolic arthropathy which occurs in families and solitary and which we defined as a special nosological unit (35, 36,) has become generally known and firmly established in rheumatology. As ensues from numerous publications, primary (idiopathic) CCA which comprises the hereditary and solitary (sporadic) form is characterized by pyrophosphate arthropathy which develops on articular cartilages not damaged by another process (13, 25, 26, 37); on the other hand as secondary CCA we consider pyrophosphate arthropathies which are associated with metabolic, endocrine or other diseases (9, 30). The common sign of both basic forms of CCA is the presence of microcrystals of calcium pyrophosphate dihydrate (CaPD) in articular cartilages, synovial fluid, or other articular structures (capsules, tendons, ligaments), characterized originally by McCarty et al. (11, 18) and later by other authors (2, 23, 27, 32). In addition to semantic (terminological) problems there were also questions of the classification of CCA because, based on an analysis of major groups of patients, it was revealed that there is a varied picture of chondrocalcinosis or pseudogout (18, 19) or deposition disease (17). of calcium pyrophosphate dihydrate crystals. In our paper we are presenting our view on the primary form of CCA and submitting the characteristics of classification which ensued from more than 20 years observation of our group of patients, in particular based on the evaluation of the beginning of the clinical and X-ray manifestations and the further development of the disease.