The objective of this study is to identify the skills measured by the questions of the Islamic Institute History books, by looking at the following: 1. What critical thinking skills do questions in History books of the Islamic Institute measure? 2. Is there statistical deviation between the percentage of the questions asked to measure the critical thinking skills in History books of the Islamic Institutes and the accepted educational percentages? 3. Is there statistical deviation in the History books questions at the three different levels in terms of critical thinking skills? To answer the above questions, the researcher made an evaluation card consisting of the five skills accepted by Watson & Glazier's (1973). The level used for the evaluation was: Available / Not Available with a slight modification to determine the type of question asked (i.e., short answer or essay question). After inquiry and certification of the evaluation card, it was implemented on the questions asked in the History books of the Islamic Institutes. Summary of results: 1. The three books in use, utilize four skills of critical thinking, i.e. eliciting, interpretation, evaluation, and preconceived knowledge (level I & II only). All levels did not measure deduction. 2. The percentage of questions that measure critical thinking in History books at the three levels is more than the accepted educational percentage which is 10%, by a statistical deviation factor of 0.01. 3. No statistical deviation in the number of the critical thinking questions between the three different levels.