The study aims to find out the impact of intensive reading strategy on English for specific purposes college students' in developing vocabulary. To achieve the aim of the study, 40 ESP College students were randomly chosen from the college of political sciences at A-Nahrain University in Iraq, the participants were in the second grade during the academic year 2017-2018. Two groups were enrolled in this experiment, 20 ESP students in the experimental group and the same number in the control group. To determine if the intensive reading strategy had an impact on ESP student's in developing vocabulary, a pre-posttest was administered for both groups. The control group was treated by the traditional way of teaching vocabulary through translating the words in Arabic language and memorizing them with the help of the teacher, while the experimental group was treated by using intensive reading strategy for about ten weeks. The chosen texts were taken from (New Head way Pre-intermediate student's book). Fill in the blank exercises had been chosen in the pre-posttest which consist of 50 items for each, the test was administered by the researcher. Based on the findings of this research, it was found that the new strategy has a positive impact on ESP College students' in mastering vocabulary that was proven from the improvement of students' mean score from pretest to posttest. Based on the results gained; it is recommended that intensive reading strategy can play a great role in mastering vocabulary.