Mass and Energy Balance (MEB) is one of basic courses in chemical engineering (CE) learning and it is needed to be passed before starting the special courses and topics in this field.  Due to the vast variety of jobs offered by chemical industries in our country, training of expert and well educated engineering students in the universities  are essential. In the present article, a literature review on the current situation of  CE and its teaching in Iranian universities are presented and the teaching approach of MEB course is discussed. The descriptive research method is applied to investigate the observable weakness sources in teaching MEB to CE students. The statistical samples include 32 CE students and specially designed questionnaires are distributed among them. Four weakness sources including (i) weakness in  basic sciences (chemistry, physics and mathematics), (ii) courses offered by low experienced and freshman teachers, (iii) students lack of self confidence and stress of failing on getting high number of  courses in one semester, as well as, (iv) lack of supplementary MEB teaching references  are considered in the questionnaire. The statistical analysis of the collected data proves the existence of weakness on MEB teaching among CE students where the main causes are (ii) and (iii) sources.  The psychological advising also decreases the number of MEB credits from 4 to 3 or adding one credit of laboratory course to the theoretical material, also, teaching MEB by more experienced teachers are suggested.