This study determined the psychometric properties of the examination items in 2011 Basic Education Certificate Examination for Basic Science. The design adopted was survey research design. The instrument for data collection was the 2011 Delta State Basic Education Certificate Examination (BECE) in Basic Science Multiple Choice Test Items. The IRT model for item selection was used to determine the estimates of the item parameters. The findings of the study revealed that 45, 45 and 40 items satisfied the IRT difficulty, discrimination and guessing parameter respectively. While 38 items satisfied the combined three IRT parameter estimates. This result revealed a significant difference in the number of the selected items that satisfied all three IRT parameter estimates in BECE Basic Science.