The flamboyant 58-year-old had undergone four operations in Cuba for a cancer that was first detected in his pelvic region in mid-2011. He vanished from public view after December 11 surgery that resulted in complications and respiratory infections.
Chavez supporters poured onto the streets, weeping and chanting 'Chavez lives!' and 'We are Chavez!'.
State TV broadcast Chavez's emotional last speech to the nation in December, shops in Caracas closed their doors for fear of looting, and condolences poured in from around the world, including messages from film maker Oliver Stone and U.N. Secretary General Ban Ki-moon.
Chavez easily won a new six-year term at an election in October and his death is devastating for millions of supporters who adored his charismatic style and oil-financed policies that brought subsidized food and free health clinics to long-neglected slums.
Apparently realising the end was nigh, Chavez named Vice President Nicolas Maduro his successor in December, just before his fourth operation, which followed months of grueling chemotherapy and radiation treatment.
Venezuela's military chiefs quickly pledged loyalty to Maduro, who will be caretaker president until elections are called within 30 days.
Chavez's corpse will lie in state at a Caracas military academy until a formal funeral ceremony on Friday, and seven days of mourning will be observed.
