The Japanese firm said 1.43 million vehicles are being recalled for air bag defects and another 2.87 million for faulty emissions controls - but it insisted it has not received any reports of injuries or fatalities related to either recall.
Some 932,000 vehicles are involved in both recalls, so the total number affected is 3.37 million.
The first recall for defective air bags affects Prius hybrids, Prius plug-ins and Lexus CT200h vehicles produced between October 2008 and April 2012 - 743,000 vehicles in Japan, 495,000 in North America, 141,000 in Europe, 9,000 in China and 46,000 in other regions.
The fault is not related to recent massive recalls of Takata air bags that has affected nearly all major car makers.
In its recall, Toyota said a small crack in some inflators in the air bags on the driver and passenger sides may expand, causing the air bags to partially inflate.
The second recall affects various Prius models, the Auris, Corolla, Zelas, Lucas and Lexus HS250h and CT200h produced from April 2006 to August 2015 - 1.55 million vehicles in Japan, 713,000 in Europe, 35,000 in China and 568,000 elsewhere, but none in North America.
Toyota said cracks can develop in the coating of emissions control parts called the canister, possibly leading to fuel leaks.
The air bag manufacturer, Autoliv, based in Stockholm, Sweden, said it is co-operating fully with the recall.
It said that in seven incidents, side curtain air bags in Prius cars partially inflated without a deployment signal.
All of the cars were parked at the time with no-one in them and there were no reported injuries.