This study examined the interrelationships among and combined effects of word reading skills and syntactic knowledge on reading prosody in fifth-grade monolingual Spanish-speaking students. We used Spanish standardized tests to assess the participants (n = 169, 79 girls) on word and pseudoword reading skills, syntactic knowledge, and reading prosody. The results revealed significant relationships among these factors and reading prosody. Word reading emerged as a pivotal predictor, whereas syntactic knowledge, although playing a smaller role compared to word reading, was linked to improvements in expression, phrasing, and the reduction of ungrammatical pauses. We also found a non-significant interaction between the independent effects of word reading and syntactic knowledge on reading prosody. The study suggests the potential benefits of integrating explicit syntactic instruction into reading curricula and intervention programs to support the development of reading prosody in Spanish.