This article shows the impact of the war on small and medium-sized businesses in Ukraine during the full-scale invasion of the Russian Federation, which started on February 24, 2022, and ended in September 2023. The object of the study is small and medium-sized enterprises that carry out business activities in Ukraine during a full-scale invasion. The research objective is to determine the business strategies and Internet marketing strategies used by small and medium-sized enterprises after full-scale invasion. The purpose of this study is to identify the most effective Internet marketing strategies and Internet marketing tools that helped small and medium-sized businesses survive the full-scale invasion of Ukraine by the Russian Federation and continue to grow. The study was conducted through in-depth interviews with representatives of small and medium-sized businesses from different regions of Ukraine and from different fields of activity. Based on the categorical analysis of the responses, three periods of enterprise survival were summarized according to the chronology of military and political events in the country. The relevant Internet marketing strategies of small and medium-sized enterprises are identified. Business strategies and Internet marketing strategies that helped small and medium-sized enterprises increase their pre-war economic performance are also highlighted. Certain reasons for the deep crisis of small and medium-sized enterprises are outlined. The intensity and effectiveness of the use of Internet marketing tools by small and medium-sized businesses after a full-scale invasion are determined. The peculiarity of the results is the study of Internet marketing strategies and successful business strategies of small and medium-sized enterprises during the war. The scientific novelty of thisstudy is that it classifies the periods of survival and growth of small and medium-sized enterprises and identifies the most effective Internet marketing strategies for these periods. The efficiency and intensity of using Internet marketing tools were also systematized. The results obtained in the study will help small and medium-sized enterprises overcome crisis conditions and identify areas for the effective use of digital marketing. The findings are of practical value for small and medium-sized enterprises in other countries where there is a possibility of armed conflict.