The movie tells the story of then zoo director Jan Zabinski and his wife Antonina, who together saved nearly 300 people.
Based on actual events, "The Zookeeper's Wife" tells the story of then zoo director Jan Zabinski and his wife Antonina, who together saved nearly 300 people, mostly Jews smuggled out of the city's ghetto, by providing them shelter in their villa basement.
Thankfully, the Nazi Germans occupying Poland never found out.
"Antonina and Jan were ordinary people who risked everything -- their safety and the safety of their children -- to save others. They fostered hope in a time that was so dark," Oscar-nominated US actress Jessica Chastain, who plays Antonina, told reporters ahead of the screening.
"What Jan and Antonina did was so extraordinary. But they did it for one very simple reason: because it was the right thing to do," director Niki Caro, who was born in New Zealand, told reporters in the Polish capital.
Israel's Yad Vashem Holocaust remembrance centre later recognised the Zabinskis as Righteous Among the Nations, an award bestowed upon non-Jews who helped Jews during the Holocaust.
The movie, which hits theatres worldwide in late March, is based on a book of the same name by American author Diane Ackerman, who relied heavily on Antonina's own memoirs from the 1960s.
Caro said she never "really wanted to do a Holocaust movie, but this one was so different."
"You know, most of our war movies are about men. But this is one that was about a woman and children and animals and all of those things interest me very much," she said.
While her husband was out most days working with the Polish underground resistance, Antonina took care of their secret guests as well an eclectic collection of pets including a piglet, an otter and a badger.
Danger was ever present, as the Nazi Germans were constantly milling around the zoo. Helping Jews -- even offering them a glass of water -- was punishable by death in occupied Poland.
Whenever the Nazis approached, Antonina would warn her secret guests by playing a special tune on the piano and they would escape outside via a tunnel in the basement.
The movie also stars German actor Daniel Bruhl and Belgian-born Johan Heldenbergh, who along with Caro and Chastain said they would join a Warsaw march on Wednesday to mark International Women's Day.
Historical records show that six million European Jews died in the Nazi German genocide during World War II. All but two of the people hidden by the Zabinskis survived.