This study explored the effect of employing two language teaching approaches, i.e., schema-based instruction (SBI) and translation-based instruction (TBI) on the structure and vocabulary knowledge as well as reading comprehension ability of sixty undergraduate students studying general English in a medical school in Mashhad, Iran. While the SBI approaches the words/phrases comprising texts as schemata having syntactic, semantic and discoursal relationships with each other, the latter considers offering their translation equivalents as the only necessary and sufficient condition to understand texts. After being divided into two groups, the learners in the experimental and control groups were taught via SBI and the TBI, respectively. The administration of a 120-item schema-based cloze multiple choice item test (SBCMCIT) developed on the syllabus and administered as a pretest at the beginning of the term showed that the two groups were homogenous. The administration of an unseen final examination (UFE) consisting of structure, vocabulary and reading comprehension subscales at the end of the term showed that the learners taught via the SBI performed significantly better than those taught via the TBI not only on the UFE and its subscales but also on the SBCMCIT administered as a post test. The findings are discussed within the specified language components and abilities.