The paper takes into consideration the basis of the contemporary knowledge of the Croatian islands. The author has presented the essential features of geographical and geopolitical space and the characteristics of evaluating the insular position. The characteristics of traffic system, the relation between the continental state and insular autonomy, cultural and linguistic peculiarities, territorial sea and maritime borders, supply and help policy and environment problems have been pointed out. Special attention has been paid to geopolitical significance of these islands in the Adriatic.