The Ukraine crisis, which started at the end of November 2013 and in April 2015 turned into armed conflict in the east of Ukraine, had a negative impact on the geopolitical situation of Poland; it compromised Poland’s security and impaired the perception of security among the majority of Polish society. This article’s objective is to outline the direct implications of the crisis and conflict in Ukraine for the security of Poland. These implications include: destabilization of the international security with serious consequences for the security of Poland; an increased sense of threat from Russia in Polish society; increased efforts of Polish foreign and security policy-makers to strengthen military defense potential; reinforcement of NATO’s cohesion and its more active involvement in Polish and Central European security; enhanced cooperation between Poland and the United States in the field of military defense; and increased threats to the economic stability of Poland. Key words: security of Poland, Ukraine conflict, Poland-Russia relations, Poland-Ukraine relations, implications of the Ukraine conflict for the security of Poland