This study analyzes the impact of certain cognitive processes on word and pseudoword reading in languages with different orthographic consistency (Spanish and Arabic) in the first year of Primary Education. The study was conducted with a group of 113 pupils from Algeria and another group of 128 pupils from Ecuador, from a middle-class background and without any special education needs. The participants were assessed in terms of their reading ability of words and pseudowords, knowledge of letters, phonological awareness, rapid automatized naming, and phonological memory. Using a correlational design, descriptive-exploratory, bivariate, and hierarchical multivariate regressions were applied to the different measures of reading in each language. The findings show that knowledge of letters, phonological awareness, rapid automatized naming, and phonological memory contribute differently to the explanation of reading ability in each group at the start of compulsory schooling. These results have important implications for the teaching of reading skills and the prevention of specific learning disabilities, as well as the theory of reading acquisition.