Abstract: A surgical tray system includes an enclosure base, a U-shaped instrument rack removably positioned within the enclosure base and capable of suspending a complete set of surgical operating instruments by their shafts, a flat operative assembly tray that may be locked into position on top of the enclosure base, above the U-shaped instrument rack, for retaining additional surgical instruments in positions that are identified by silkscreened outlines of those additional instruments, and a cover that may be locked into position on top of the operative assembly tray, thereby covering the enclosure base, the U-shaped instrument rack positioned within the enclosure base, and the operative assembly tray. One or more additional trays, such as a diagnostic assembly tray, for retaining additional instruments required in connection with a particular surgical procedure, may be stacked above or below the operative assembly tray or they may be included within a separate tray having its own enclosure base and cover.