We explore the potential of a computer-adaptive decoding game in Spanish to increase the decoding skills and oral reading fluency in Spanish and English of bilingual students. Participants were 78 first-grade Spanish-speaking students attending bilingual programs in five classrooms in Texas. Classrooms were randomly assigned to the treatment (i.e., where students played Graphogame Spanish) for 16 weeks for ten minutes per day (n = 3) versus business as usual instruction (n = 2). Results indicate that students at some risk on Spanish pseudoword reading appeared to benefit the most from playing the game. Analysis of gains suggests a potentially small, but meaningful educational effect of the game on Spanish oral reading fluency and English pseudoword reading when taking Spanish decoding skills at pretest into account. Students indicated that they enjoyed playing the game, and that the game helped them improve their reading skills. Teachers perceived the game as an engaging tool for students to use during small-group instruction or during independent time in a Response-to-Intervention approach. We discuss our mixed results in the context of using computer-adaptive games to improve the academic outcomes of bilingual students.