This study investigated the effectiveness of comprehension-based processing instruction (PI) and the production-oriented approach (POA) on Chinese L1 learners’ acquisition of complex structures in L2 English. Two groups of first-year college students (n = 94) participated in an intensive skill-integrated course for two months. They were randomly assigned to either a processing instruction or a POA class. Their recognition and production of six target forms (present/past perfect, temporal adverbial clauses, indicative/subjunctive conditionals, and oblique relative clauses) were assessed in a pre-, post-, and delayed-test design. Overall, the POA group made greater progress than the PI group in both receptive and productive tasks, suggesting that POA can be a viable instructional strategy to facilitate L2 learners’ acquisition of complex grammatical features. POA was also found to be effective in fostering learners’ self-efficacy beliefs in L2 production. However, it did not induce them to apply those structures in spontaneous production contexts. PI was not as effective as POA in improving the students’ grammatical accuracy, while it nevertheless enhanced their intake of the target forms to a considerable degree.