Through the introduction of different dimensions of vocabulary knowledge, various studies attempted to examine numerous effective factors on these dimensions. The present study aimed to show the effects of different vocabulary learning styles through extensive and intensive reading programs on depth and breadth aspects of vocabulary knowledge. To achieve this goal, 45 sophomore undergraduate students of English language teaching and translation in Payam-e-Noor University participated in this study. Initially, in order to homogenize the learners based on their level of language proficiency, MEPT was administered. Then, by measuring the mean and standard deviation of participants’ scores, the number of participants reduced to 35. The ultimate subjects’ scores on the reading comprehension items of MEPT show that they are all at the intermediate level of reading ability. Participants divided into three experimental groups randomly: two groups were in the extensive reading program with different form-focused and meaning-focused tasks as incidental vocabulary learning style. And the third group was in the intensive reading program as intentional vocabulary learning style. Participants in these experimental groups read long stories or passages per week with ten goal-oriented words. After 8 weeks, Word Associates Test (WAT) and Vocabulary Knowledge Scale (VKS) were administered to measure the acquired knowledge of new words and also, determining the effects of various learning styles on different dimensions of vocabulary knowledge. The results of Paired-samples and Independent T-tests revealed that both incidental and intentional groups developed in the period between the pre- and post-test, but, there was a significant difference between the effects of incidental vocabulary learning in the form of ER program and intentional vocabulary learning in the form of IR program. Moreover, there was a significant difference between the effects of the form-focused and meaning-focused task.