Undercover police killed the 27-year-old electrician on a Tube train at Stockwell Underground station. They had identified him as a terrorist, and shot him on 22 July, one day after four terrorists' bombs failed to detonate in London.
Asked if he considered quitting following criticism over the incident, Sir Ian told BBC's News 24 Hardtalk programme: "Yes. If somebody makes those comments you are not just going to brush it off. No one in their right mind would be arrogant enough to rule it out."
But asked how close he came he said: "Not very close at all, because the big job is to defend this country against terrorism. That is what we are here to do."
When asked if he would resign if he were condemned by the Independent Police Complaints Commission report into the shooting, he said: "It depends on the level of condemnation."
Sir Ian also expressed regret that reports carrying false details about Mr de Menezes shortly after he was shot were not corrected.
Some claimed that he had aroused suspicion by wearing a heavy padded coat and had vaulted over a ticket barrier into the station, although Sir Ian said these reports did not come from a police source.
He said: "It was a mistake not to have corrected the misinformation. I wish we'd done that sooner."