Objective: To compare screening strategies for type 2 diabetes mellitus (DM), impaired glucose tolerance (pre-DM), and insulin resistance (IR) in women with polycystic ovary syndrome (PCOS). Design: Prospective study. Setting: Academic reproductive endocrinology practice. Patient(s): Adult women with PCOS (n = 111). Intervention(s): None. Main Outcome Measure(s): Subjects were screened for pre-DM and DM using a 2-hour glucose tolerance test (GTT), hemoglobin A1c (HbA1c), or fasting plasma glucose (FPG) and for IR using homeostasis model assessment (HOMA), insulin levels (fasting and 2 hours after 75 glucose load), or obesity. Screening approaches were compared using positive and negative percent agreement and Cohen's kappa (κ). Result(s): DM and pre-DM were diagnosed by GTT in 4% and 20% of subjects, respectively. Screening with FPG failed to identify 41% of pre-DM and 20% of DM subjects. GTT and HbA1c had only fair agreement (κ = 0.29). IR was diagnosed in 24% of subjects with pre-DM or DM and in 56% of the remaining subjects using HOMA and insulin levels. HOMA and elevated insulin levels demonstrated substantial agreement for detecting IR (κ = 0.70-0.73). Obesity demonstrated fair to slight agreement (κ = 0.33-0.18). Conclusion(s): Women with PCOS should be screened for Pre-DM and DM using GTT or HbA1c, and those with Pre-DM or DM are presumed to have IR. In the rest, IR can be detected using either HOMA or insulin levels. © 2011 American Society for Reproductive Medicine, Published by Elsevier Inc.