This paper reports a study which examines how text-based vocabulary instruction influences English as a foreign language (EFL) freshmen’s reading comprehension and explore their perceptions on this type of instruction in reading comprehension. It was a quasi- experimental study with control and experimental groups including eighty freshmen at a university. The quantitative data from reading tests for pre-test and post-test were used to examine students’ reading comprehension over nine weeks. The qualitative analysis used semi-structured interviews to examine students’ perceptions towards text-based vocabulary instruction in reading comprehension. The findings reveal that text-based vocabulary instruction influenced positively students’ reading achievement after the experiment and that they had positive perceptions towards this type of instruction in their reading lessons.