This study investigates the pronunciation difficulty of selected English consonant clusters (CCs) encountered by Saudi EFL learners. The sample consisted of 134 female Saudi EFL students in their freshman year in the English Department at Najran University. Two instruments were used: a pronunciation test that assessed participants’ CC pronunciations in the onset and coda positions and a questionnaire that explored participants’ attitudes towards their CC pronunciations. This study provides detailed data on the participants’ pronunciation difficulties using Optimality Theory (OT). The results showed that the participants encountered CC pronunciation difficulties in both the onset and coda positions. However, most errors occurred in the coda position, especially for the four-consonant pattern (-CCCC). Participants used different strategies to simplify their CC pronunciations: epenthesis, deletion, substitution, or some combination thereof. Questionnaire data indicated that the participants attributed their pronunciation difficulties to inadequate knowledge of the pronunciation rules, insufficient language instruction, and native-language influence. The participants proffered some remedies to their difficulties, which included doing more pronunciation drills and offering a new course focused primarily on correct pronunciation. OT analysis revealed that onset clusters were mainly influenced by L1 ranking constraints whereas coda clusters were more influenced by universal Markedness constraints. OT indicated that the tendency to satisfy Markedness constraints over the Faithfulness constraints led the participants to use the above-mentioned simplification strategies.