"With Broz's death, we are left without one of the last most reliable witnesses of our former country's history," BBC quoted Serbian Prime Minister Ivica Dacic as saying in a message of condolence.
Jovanka Broz joined Tito, who fought the Nazi occupation in World War-II, when she was just 17.
She was Tito's personal secretary before becoming his third wife in 1952. However after Tito's death in 1980 she lived in isolation, and under house arrest for a time. She was admitted to hospital in August with serious heart ailments.