The subject of the research is an attitude of Chief National Committee (CNC), significant Polish, political organization in the time of World War I, towards the Ukrainian national movement and its postulates. CNC came into being in august 1914 as political background of Polish Legions fighting in Austro-Hungarian army. Chief National Committee also played the role of a main exponent of Austro-Polish conception: an idea of creation self-governing Poland under the rule of Habsburg dynasty. In the first two years of war this conception had the strongest position among the others, numerous ideas of reconstruction of Poland. The same time brought also the rapid Ukrainian national rebirth. Ukrainians, mainly these living in Austro-Hungarian Galicia, firmly demanded to single out a new province of the Habsburg monarchy, covering the area of Eastern Galicia and city of Lvov. This idea was of course contradictory to the Polish plans, so campaigning for its own conceptions Chief National Committee had to face Ukrainian demands. Aim of the article is to present these works and opinions of politicians and journalists working for CNC, that refer to the Ukrainian question. Remarkable attention is also paid to the Polish ideas of Ukrainian presence and autonomy in future, independent Poland. Finally, both mental and political sources of the attitude of Polish activists towards Ukrainian national movement are briefly investigated in this work. Problems touched in this work seem to be crucial to understand the fact, that after final collapse of the Habsburg monarchy in autumn 1918, unsolved Polish-Ukrainian conflict led to the breakout of a regular war. Article is based on scientific descriptions, memoirs and archival materials available in the State Archive in Cracow.