This review presents the latest data on the relations between the genetic basis of primary ciliary dyskinesia (PCD) and improvement of its diagnosis. PCD is a rare disorder caused by mutations in one of many ciliary genes. The PCD diagnosis is challenging and requires a well described clinical phenotype combined with the identification of abnormalities in ciliary ultrastructure and beating pattern, as well as of the underlying genetic cause. New technologies available in the genetic studies have a great influence on the number of identified PCD-causative genes and mutations and this number is bound to rise. The current knowledge can already be used to create new genetic tests for PCD which can accelerate the correct diagnosis. (By Dr. Małgorzata Kurkowiak, http://jmg.bmj.com/content/early/2014/10/28/jmedgenet-2014-102755 )