Over the rest of September, Cubans will meet in small groups to nominate municipal representatives, the first in a series of votes for local, provincial and, finally, national officials.
In the second electoral stage, a commission dominated by government-linked organisations will pick all the candidates for elections to provincial assemblies and Cuba’s national assembly.
The national assembly is expected to pick the President and members of the powerful Council of State by February.
Mr. Castro has said he will leave the presidency by that date but he is expected to remain head of the Communist Party, giving him power that may be equal to or greater than the new president’s.
Cuban officials say 12,515 block-level districts will nominate candidates for city council elections to be held Oct. 22.
An opposition coalition says it expects 170 dissidents to seek nomination in the bloc-level meetings that began on Monday. A few opposition candidates made it to that stage previously but were defeated.
Local elections
At one session on Monday evening, about 400 people gathered to choose their neighbourhood’s candidate, meeting in front of a house adorned with photos of the late Fidel Castro and Cuban flags.
Cuba’s new President has long been expected to be First Vice President Miguel Diaz-Canel, a 57-year-old career party official who has maintained a low public profile in recent years.