Military organizations have adapted to the logic and dynamics of social media to transmit their institutional narratives. Instagram is the most popular social network, but one of the most understudied in relation to the Armed Forces. This research note presents a comparative study of the content of the official accounts of the Spanish, French, the United States, Israeli, and Australian armies throughout 2021 ( n = 1,922). The specific objectives are to describe and analyze the hashtags, the accounts mentioned, and the main topics of the post. Results show that armies can convey multiple messages in a single post, and reveal that armies make similar use of Instagram, notwithstanding the various differences between Israel and the other armies due to organizational and contextual elements.