This study was partly conducted in order to establish a base level of information on the knowledge levels of Tanzania students in the area ofintegrated science process skills. Specifically the study assessed students’ competence in formulating and identifying testable hypotheses, in controlling variables, in designing experiments, in analyzing data and in defining operationally. Integrated science process skills, as in the Tanzania´s Competence Based Curriculum of 2005, have been identified in the science education literature as an effective inquiry method of teaching science. Advanced level biology students in Morogoro municipality schools were taken as a case study. This study aimed at assessing the knowledge level of advanced level Biology students in the Municipality of Morogoro of science process skills. Based on the Biology process skills test (BPST) scores, it was found that Biology students in Morogoro Municipality had barely average knowledge level of integrated science process skills. The mean of test scores was 17.2 items out of 35 items in the test corresponding to 49.1%. However, Morogoro students performed relative better on items measuring their ability in identifying and controlling variables with score mean of 4.05 out of 07 items and they performed extremely poor on items which measured their skills in analyzing and interpreting data with the mean of 2.34 out of 07 items.