On January 20, 2015, Rasmus signed a one-year, $8 million contract with the Houston Astros. As an everyday starter for the Astros, he finished the 2015 season with a .238 average, 25 home runs, and 61 RBIs in 137 games played.He batted very well during the last month of the regular season and his success would continue into the postseason.In the2015 American League Wild Card Game against the New York Yankees, Rasmus hit a solo home run to score the first run of an eventual 3-0 win that advanced the Astros to the ALDS.[33] He also homered in each of the first two games of the ALDS. In the process he set an MLB record for having an extra-base hit in each of his first six career postseason games, dating back to his tenure with the Cardinals. The Astros went on to lose the series and Rasmus finished the playoffs leading his team in nearly every offensive category. He batted 7 for 17 (.412 average) along with 4 HRs, 6 RBIs, 7 BBs, and an OPS of 1.760.[