The former bus driver rose through the political ranks with his faithful support of the late President.
More than 20 world leaders are expected to attend the funeral today, but there will be no burial as he will be embalmed.
Thousands flocked to the streets of Caracas to see the coffin of Chavez travel through the city to lie in state until Friday's funeral.
It is astonishing that Hugo Chavez's cancer ridden corpse is two be embalmed and put on display in a military museum, the same museum where he was captured after leading a failed coup 20 years ago.
Embalming and displaying him, the showman's final act.
Meanwhile the veneration and deification of Chavez continues, with people queuing comparing him to Christ, his face on crucifix scenes.
The cult of Chavez was strong in his lifetime. It is about to get a much more powerful.
Venezuelan authorities estimate that well over two million people have now paid their respects to their dead President Hugo Chavez.
More than 20 world leaders are expected to attend the funeral tomorrow, including Iran's Ahmadinejad and leaders from Argentina, Bolivia, Uruguay.
There will be a funeral for Chavez, but he won't be buried. Authorities still can't decide where he will rest. But he will be embalmed, like Lenin.
Hundreds of thousands of Venezuelans joined the crush to view Hugo Chavez's body lying in state in the capital Caracus today.
Responding to the overwhelming demand, and the desire that Chavez should be "always be with the people", it was announced tonight that the leader will remain on display permanently.
ITV News International Editor Bill Neely reports from Caracas:
Venezuela's Vice President Nicolas Maduro has just announced on national TV that Hugo Chavez's funeral will take place tomorrow morning.
Around 30 heads of state are expected to attend along with delegations from 50 countries.
Maduro also said that Chavez's body will return to lying in state for public viewing for seven further days after the funeral to allow more people to see him.
Chavez's body will then be preserved like that of Lenin and Mao Zedong so "he will always be with the people". A special tomb is now under construction in the mountains where he launched his revolution.
Maduro again called for calm and thanked the public for respecting the solemnity of the occasion.
The body of Venezuela's late president Hugo Chavez will be embalmed and laid to rest at a military museum in the capital Caracas.
Acting President Nicolas Maduro said Chavez would lie in state for a further seven days so Venezuelans waiting in long lines to view him would be able to do so.
Maduro added that his body would later to moved from the military museum to his final burial site. It was not immediately clear where that would be.
Venezuela's Vice President Nicolas Maduro has declared seven more days of mourning for Hugo Chavez, Reuters reports.
Dozens of people were injured in a crush today as hundreds of thousands of people queued to see the mortal remains of Hugo Chavez.
A continuous stream of mourners filed past the leader's open casket in the Military Academy in Venezuela's capital Caracas.
Outside the Academy, riot police struggled to maintain order and were seen carrying away several people injured in the crush.
Barriers failed to hold back the surge of people, some of whom had waited for more than 18 hours to bid their leader farewell.
Most people queuing to see Hugo Chavez are dressed in red - the colour of his revolution.
Many tell me the revolution will live on.
The funeral begins tomorrow at 8am local time (12:30pm GMT.)
Huge crowds surge forward and crush barriers fail to hold them, soldiers are fighting to push them back. Many are hurt.