Peters, who has been critical of the Black Lives Matter protests in New Zealand, used the phrase to highlight that older New Zealanders are being abused.
"Ageism is like racism, but not as attractive to the media," he said.
"We, and you, need to rise up and say, 'senior lives matter'."
Peters wants to install a Commissioner for Seniors whose job would be to hold the government to account on its record and stop elder abuse.
He also told his supporters that his party has "unfinished business" with the SuperGold Card.
"Our plan now is for Phase Two of the SuperGold Card," he said.
The first phase was rolled out during the first term of this Government and included a greater number of businesses who offered a seniors discount.
Peters said he plans to increase that number even further.
"We will combine the SuperGold Card members into a 'Super Buying Group' and create super deals with power companies, telcos and internet companies, to give you more savings."
He also highlighted the party's free dental care to superannuates policy and promised not to let other parties add a wealth, or property tax to seniors' homes.
Peters targeted other political parties who, he said, "will target seniors as being past their use by date".
He did not, however, say which parties he was talking about but did reference a phrase used by the Green Party.
"Some think that 'tax is love' - it isn't. Instead of seeing you as a role model, they are envious of what you have done and saved during your hard-working life."