The focus of this study is on the possible effects of phonological interference on the reading achievement of Spanish-speaking Puerto Rican first graders. Specifically, the study explored the relationship between standard English auditory discrimination and first-grade reading achievement. Subjects for the study were 32 female and 20 male students from six Trenton, New Jersey, elementary schools. The instruments used were the two forms of the experimental auditory discrimination test and Form 1 of the Gates-MacGinitie Reading Test. Results show that low positive but significant correlations were found between scores on both forms of the auditory discrimination test and composite reading scores, between scores on both auditory discrimination test forms and vocabulary subtest scores, and between scores on Form II of the auditory discrimination test and comprehension subtest scores. A bibliography and six appendixes containing material related to the study are included in the thesis. (JM)