The 74-year-old Fujimori is serving a 25-year sentence for crimes against humanity related to death-squad killings during his corruption-ridden 1990s rule.
Keiko Fujimori made the announcement Friday after visiting her father at a hospital. He was operated on in August for the fifth time for a pre-cancerous lesion on his tongue and the wound has had trouble healing.
President Ollanta Humala said earlier this week that he hoped any request for a pardon would not be politically motivated.
Humala defeated Keiko Fujimori in June 2011 elections.