This study explores the impact of ‘Scientific Communication’ (SC) skills instruction on students’ performances in scientific literacy assessment tasks. We present a general model for skills instruction, characterized by explicit and spiral instruction, integration into content learning, practice in several scientific topics, and application of performance tasks. The model was applied through an instructional program that focuses on the following learning skills: information retrieval, scientific reading and writing, listening and observing, data representation, and knowledge presentation. Throughout the 7th–8th grades, 160 students learned the whole program or one of its components: structured instruction (SI) of SC skills, or performance tasks (PT). A comparison group of 42 students did not receive instruction of SC skills. Students’ performances were assessed through a questionnaire and a complex task that measured students’ scientific content knowledge, SC skills, and the quality of the final products. Results indicated that students who learned the whole program or one of its components achieved higher scores in all categories than the comparison group students. High achievers can benefit from just one component of the program: either structured instruction (SI) or learning from practice (PT). However, they can hardly acquire SC skills spontaneously. Low and average achievers require both components of the SC program to improve their performances. Results show that without planned intervention, the spontaneous attainment of SC skills occurs only to a limited extent. Systematic teaching of skills can make a significant difference. The explicit instruction of skills integrated into scientific topics, the opportunities to implement the skills in different contexts, the role of performance tasks as ‘assessment for learning’—all these features are important and necessary for improving students’ scientific literacy. Our general model of skills instruction can be applied to the instruction of other high-order skills. Its application can lead to the realization of the central goal of science education: literate students possessing scientific knowledge.