This study examines how topic familiarity and working memory capacity affect beginning Spanish learners' reading comprehension and their processing of future tense morphology. Participants included 94 adult learners from an accelerated, beginning Spanish course. In addition to completing a computerized version of a reading span test as a measure of working memory capacity, all learners read texts about familiar or unfamiliar topics and completed recall protocols to measure passage comprehension. They also completed form recognition and tense identification tests to determine processing of future tense morphology. The results revealed consistent effects for topic familiarity on all tasks. Although differences in working memory capacity played some role in learners' comprehension and processing grammatical form, significant findings for working memory emerged depending on participants' previous knowledge about text topics.