The Experienced Curriculum” is one of the curriculums performed in the educational systems on which several different studies have been done. “The Experienced Curriculum” is of different levels whose first one is the hidden curriculum. This curriculum can be affected by different factors which have been categorized into four categories namely, educational, social, and geographical in this study. Despite the plethora of studies done on the experienced curriculum, a few field studies have been done on the effective factors in the curriculum. The present study aims at exploring the effective factors in the hidden curriculum of “Islamic Thoughts” course for B.A. students. The required data have been collected by questionnaire. 210 students have been randomly selected as the statistical sample from among 650 students studying at one of Tehran’s universities in 2010-2011 semesters. The Pearson statistical test has been used to analyze the collected data. The findings of the study demonstrated that all educational, social, and geographical factors and their related subsets have significant relationships with hidden curriculum of “Islamic Thoughts” course, but the results of the total Regression only proved the following significant relationship: educational factors and teacher, content and evaluation variables; social variables and the family media, friends and classmate variables; social variables and study, satisfaction of religious education; and the geographical variables with the residential place variables. The findings also proved that “satisfaction of religious education”, “teachers of the religious course”, “friends and classmates”, “media and religious studies” have the most significant relationships with the hidden curriculum of “Islamic Thoughts” respectively.