There has yet to be an official definition of what classifies a timepiece as a Grand Complication, there is however an understanding among watchmakers and watch connoisseur alike that a watch must meet certain guidelines to acquire this grand title. One could be safe to assume that a Grand Complication timepiece will always contains at least three complications, and one of those will undoubtedly be a Perpetual Calendar, a Tourbillon, or the Minute Repeater.

The first of these complications, the perpetual calendar, is a mechanism that automatically takes into account the varying number of days in each month as well as leap years - many also contain a moonphase function. Most often, the perpetual calendar is based on the Gregorian calendar which does not need to be corrected for more then a century. The second complication in the "Grand" category is the tourbillon, which was invented to reduce the debilitating effects of gravity on watches, which ultimately lead to inaccurate timekeeping. With a tourbillon, the negative effects of gravity ultimate cancel themselves out. Lastly, the minute repeater is a device that the current time is announced by means of a combination of sounds that represent the hour, quarter hour, and minute. It is arguably the most difficult to construct, and no two sound exactly alike.

A supreme test of a designer's expertise and watchmakers skill is the creation of a Complicated watch. IWC was the first to create a Grand Complication in a pocket watch, it was introduced in 1890 with more than 1300 mechanical parts. 100 years later, they made history again when the created the IWC Grand Complication Wristwatch - a watch still in production today with a limited release of just 50 pieces a year. Patek Philippe has built some of the world's finest examples of complicated timepieces. One recent example, Patek Philippe Reference # 5004 is a split seconds chronograph that is the most complicated model in Patek Philippe's line of stopwatches.