This study examines the relationship between simultaneous and successive processing (the Planning, Attention, Simultaneous and Successive processing [PASS] theory processes) and reading skills in English as a foreign language (EFL). A group of 81 children were administered two batteries of tests. One was used to measure EFL reading skills, while the other one assessed simultaneous and successive processing. We hypothesised (1) cognitive processes to predict reading ability, as well as (2) the presence of a significant relationship between (3) simultaneous processing and reading comprehension and (4) successive processing and letter and word decoding. The findings confirmed that the anticipated relationships between these domains exist and are of moderate effect size. The research has helped to contribute to the understanding of how simultaneous and successive processing can affect EFL reading skills both on the level of basic word and letter decoding and reading comprehension.