Officers caught the reptile after a passer-by spotted it as it slithered down Ringvägen on the capital's Södermalm island at around 1.20am on Monday.
“They caught it in a paper bag and took it to the station,” police control room officer John Larsson told the Aftonbladet tabloid.
But after examining the snake later on Monday morning, Jonas Wahlström, head of the aquarium at Stockholm's Skansen zoo, was able to reassure officers that there was no cause to feel rattled about the scary find.
“Usually when the police calls in the middle of the night, it's in regards to an escaped corn snake – we received one a week ago and this one was also a corn snake. It's small and harmless and very common as a pet,” he told The Local.
A North American breed, the corn snake grows to around 1.2-1.8 metres (3.9-6ft) and can live to be more than 20 years if it is kept in captivity. Its relatively docile nature makes them popular among reptile owners.
“There are thousands of these owned as pets in Sweden and there's even a large number of corn snakes that escape from their homes. Our advice to pet snake owners is to carefully consider their decision before buying a snake and of course to keep a close eye on it at home,” said Wahlström.
The runaway reptile is now staying at the Skansen Aquarium, part of the world's first open-air museum founded in 1891. The zoo area of the attraction is home to about 200 rare and exotic animal species, including monkeys, lizards, crocodiles, sloths and spiders.
“The Skansen Aquarium mostly works with endangered species and this corn snake is officially lost property, so hopefully the rightful owner appears to collect his or her pet. If the owner doesn't get in touch within a fortnight the police will tell us to take care of the snake,” said Wahlström.
Meanwhile, a python which went on the slither in a Malmö park earlier in July is believed to still be at large somewhere in Pildammsparken in southern Sweden.
“We've been looking in the pond and the areas around the pond, but it's like looking for a needle in a haystack,” Joakim Ljungström at Malmö Reptile Centre told southern Swedish daily Sydsvenskan earlier this month.
Interview and additional research by Elin Jönsson.