The present study aimed to uncover the extent of availability of critical thinking skills within the social studies activities books and the range of acquisition of such skills by students. To this end, the researcher developed a list containing twenty-two skills targeting critical thinking, which he, later on, submitted to a team of referees to assess it's validity. Beside that the researcher designed a test to measure students acquisition of critical thinking skills. This test was also applied to other students not included in the studies sample for consistency (0.70). The study sample consisted of all the social studies textbooks taught in grades 5-8 in Basic Education. The activities included therein were analyzed in the light of critical thinking skills. The student sample was made up of (80) boys and( 80) girls in grade 8 of Basic Education. The results relating to the extent of availability of critical thinking skills in social studies activities books show the more available skills at determining undeclared hypothesis, gathering data related to a topic and making inferences were ( 16.16%),( 15.09%) and ( 10.48%) respectively. It is worth noting that the skills relating to differentiating between primary and secondary sources on the one hand, checking out matches or mismatches between various evidence, were not attended to in any of the activities provided in the social studies textbooks. As for the extent to which eight graders acquire the critical thinking skills provided in the social studies textbook activities, the study results revealed the following: A- The students are weak at acquiring critical thinking skill ( up to 38%) B- Their skill at determining evidence data for a given hypothesis (74.04%). C- Their skill at checking whether some particular information refers exactly to the references mentioned ( 71.03%). D- Their skill at making appropriate decisions on the ground of given results reached (60%). Conversely the types of skills the students acquired least tend to the following areas: A- Distinguishing opinions from facts (20%). B- Deduction (15%). C- Sequencing / follow-up ( 14.04%). The study results also exhibit considerable discrepancies between boys and girls and in favor of the latter ( a = 0.05). Based on the research result mentioned above, the researcher brought about a set of recommendations and suggestions for further scientific researches to supplement the present one.