The objective of this paper is to analyse normative grounds for the president’s exercise of command over the Polish Armed Forces during a war. As a result of his research conducted, the author states that significance of the head of the state as regards military affairs in the period of war is subject to visible formal enhancement as compared to the period of peace. This is mainly due to the direct method of fulfilment of the president’s functions under Article 134, par. 1 of the Constitution and the president’s power to appoint the Commander-in-Chief of the Armed Forces, who reports directly to the president. However, effective exercise of the president’s command over the army during a war may prove difficult. The reasons for this may be, among others, problems in determining, whether there is a period of war in the territory of the Republic of Poland, it is necessary to act jointly and cooperate with the Prime Minister or there are no legal provisions relating to functions of the state during a war, including, supervision over defense of the state. Additionally, the author indicates to some legal gaps relating to the institution of Commander-in-Chief of the Armed Forces, as a result of which the current normative status of the subject issue has to be evaluated as very poor.