According to J.C. Piette the defining and classifying of criteria for antiphospholipid syndrome (APS) were in 1996, a “mission impossible”. There was no clear evidence that APS should be regarded a unique entity. The categorization between “primary” and “secondary” APS was difficult to achieve. In the present paper the history of APS criteria is discussed. After the last decade we have formulated a new version for the classification criteria of APS – nevertheless many questions require further studies: – etiopathogenesis of APS is not clear, – “primary” or “secondary” APS remains unresolved problem, – multiple additional factors for thrombosis demand identification, – it ought to be specified which antibodies–apart of included in criteria – could be markers in “seronegative” APS. We are still waiting for the “common biological denominator” based on scoring system encompassing immunological abnormalities as well as clinical symptoms, to formulate the “ideal” criteria for APS.