THIS STUDY INVESTIGATED THE EFFECTS OF THE TEACHER'S USE OF GUIDED INQUIRY IN A FIFTH GRADE SCIENCE CLASSROOM. INQUIRY IS SUPPORTED BY THE NATIONAL RESEARCH COUNCIL(2000), AND INDICATES THAT ALL STUDENTS SHOULD DEVELOP THE ABILITIES NECESSARY TO DO SCIENTIFIC INQUIRY AND DEVELOP UNDERSTANDINGS ABOUT SCIENTIFIC INQUIRY (P.21). THIS STUDY WAS A QUALITATIVE ACTION RESEARCH DESIGN, FOCUSING ON SEVENTEEN STUDENTS AND THEIR RESPONSES TO A GUIDED INQUIRY METHOD OF SCIENCE INSTRUCTION ON MATTER, ENERGY AND MOTION, AND EARTH AND SPACE. AN ANALYSIS OF STUDENTS' PERFORMANCE AND STUDENTS' ATTITUDES ABOUT SCIENCE IN THE CLASSROOM WAS CONDUCTED ABOUT EACH UNIT OF INSTRUCTION. THE 5-E MODEL OF GUIDED INQUIRY WAS USED TO ELICIT MEANINGFUL UNDERSTANDINGS WHILE COMPLETING THE UNITS OF MATTER, ENERGY AND MOTION, AND EARTH AND SPACE. STUDENTS WORKED IN COOPERATIVE GROUPS TO SUPPORT LAB ACTIVITIES, WHICH REQUIRED EACH MEMBER TO PARTICIPATE IN THE INVESTIGATIONS, PROJECTS, AND PRESENTATIONS. STUDENTS KEPT JOURNALS, RECORDED THEIR FINDINGS, AND WROTE RESPONSES ABOUT THEIR FINDINGS AND FEELINGS ON THE ACTIVITIES IN WHICH THEY WERE ENGAGED. STUDENTS' ATTITUDES WERE AFFECTED POSITIVELY BY THE USE OF GUIDED INQUIRY IN LEARNING SCIENCE. STUDENTS' PERFORMANCE FOR LAB ACTIVITIES WAS ALSO POSITIVE AND WAS SUPPORTED BY STUDENTS' RESPONSES IN JOURNALS, TEACHER OBSERVATIONS, AND PERFORMANCE TASKS. THIS STUDY SUPPORTS GUIDED INQUIRY IN THE SCIENCE CLASSROOM FOR IMPROVING STUDENTS' ATTIDUES AND STUDENTS' PERFORMANCE DURING CLASSROOM ACTIVITES.