The pig is a valuable animal model in diabetes research; however, standardized protocols are essential for evaluating in vivo metabolism. Here, we present a protocol for in vivo assessment of glucose control and insulin secretion and sensitivity in the pig. We describe steps for catheter implantation, testing of intravenous glucose tolerance, performance of hyperinsulinemic-euglycemic clamps (HECs) and hyperglycemic clamps (HGCs), and blood processing. We then detail procedures for analysis of plasma glucose, insulin, glucagon, and C-peptide concentrations as well as data analysis. For complete details on the use and execution of this protocol, please refer to Renner et al.1 and Renner et al.2.