Current phonological awareness assessment procedures consider only the total score a child achieves. Such an approach may result in children who achieve the same total score receiving the same instruction even though the configuration of their errors represent fundamental knowledge differences. The purpose of this study was to develop a tool for phonological awareness error classification and explore the types of errors made by 215 grade one children from low socioeconomic backgrounds on a phonological awareness test. Twenty-one distinct errors were identified and classified into eight categories. The most frequently occurring error category was Additions followed by Segmentations, Substitutions, Insertions, Repetitions, Omissions, Reversals, and Multiple Errors. Examination of a subsample of study participants who were classified as high and low reading performers revealed differences in the both the degree and type of errors exhibited. Low reading performers exhibited significantly more Insertion, Omission, Segmentation, and Substitution errors. Knowledge of child errors has the potential to enhance understanding and interpretation of child test performance and subsequent instructional recommendations.