The medley women could not challenge for a medal in the Olympic Games final.
They finished seventh with a time of 3.56,92 for Hanna Rosvall, Sophie Hansson, Louise Hansson, and Sarah Sjöström.
The USA took gold with a world record time of 3.49,63 and outclassed second-place Australia and third-place China.
Sweden was almost four seconds from a bronze medal.
We're a bit behind, but we're doing our best and we're swimming in a final that's the fastest in world history, and for little Sweden to be able to be there and fight is really cool, says Sophie Hansson.
Sweden took World Championship silver in February in Qatar, but then the top teams were missing many of their most renowned swimmers.
In the Olympic Games in Tokyo, Sweden finished fifth.
China won the men's 4x100 meter medley ahead of the USA and France.