Polysemes are words that have multiple meanings. They exist in all languages as in Arabic [Arabic characters] and English "base," "plant," "system," "present," "left." A sample of Arabic and English polyseme translation errors was collected from homework-assignments and exams to explore the difficulties that student-translators have in translating English and Arabic polysemes. Data analysis showed that the students made more errors in translating Arabic polysemes to English than English polysemes to Arabic. They made more errors in translation polysemous compounds than single-word polysemes and the equivalent compounds had collocation errors. The students utilized different faulty strategies in translating polysemes, especially in source texts which have one-to-many equivalents ("system," "affairs"). They tend to overgeneralize the equivalent they know to all contexts ("develop," "system"), not the one suitable for a particular context/domain (*"chemical plants"; "under president"). They resorted to literal translation, i.e., word for word translation rather than using fixed formulaic equivalents that are dissimilar in structure to the source polyseme. They also overgeneralized the same equivalent to all contexts ("develop," "system"; "association"), although each shade of meaning has a different equivalent. Faulty translation of polysemic words may be due to inadequate L1 competence such as the availability of different regional Arabic designations for 'parliament' and the different designations used in American and British English for ([Arabic characters];(lack of proficiency in EFL, i.e. limited vocabulary knowledge; unfamiliarity with specialized meanings (*"chemical plants") and commonly used equivalents for 'affairs; resources'; lack of world knowledge ("exchange programs"; [Arabic characters] and others. The study recommends that translation instructors develop students' vocabulary knowledge, word knowledge accuracy, schemata and world knowledge, metacognitive skills, i.e., thinking processes while translating, word and context analysis skills, i.e., using semantic and structural contextual clues to figure out the meaning of polysemes; and identifying the domain in which a polyseme is used.