Col. Krzysztof Olszowiec was accused of failure to ensure proper security for the president during his trip to Georgia on Sunday for the fourth anniversary of the "rose revolution" that brought Mikheil Saakashvili to power.
He was dismissed despite objections from Kaczynski, newspapers said.
Polish Foreign Ministry spokesman Piotr Paskowski was quoted on Thursday by Polish media as saying the trip to the border area with Russian-backed South Ossetia was a last-minute invitation from Saakashvili.
Saakashvili claimed Russian troops had fired shots at the presidents' motorcade, while Moscow said the incident was staged as part of Georgian propaganda.
Poland's government, which conducted an investigation into the incident, issued a report on Thursday saying it was not clear who opened fire.
Speaking after the incident, Kaczynski said he and the Georgian leader had heard Kalashnikov assault rifles being fired about 30 meters from their cars. He said it was unclear whether the shots had been aimed at them or were fired into the air.
Poland strongly backed Georgia in its five-day war with Russia over South Ossetia in August. Moscow has since recognized Ossetia and the other Georgian rebel region, Abkhazia, as independent states, and sent additional troops there.