A bio-survey mission was an scientific assignment undertaken by governments of different planets to distant star systems.

In 2369, the Klingon vessel IKS Toh'Kaht undertook a bio-survey mission for the Klingon High Council in the Gamma Quadrant. The crew proudly boasted about it while drinking in Quark's on Deep Space 9, something that Quark couldn't see the honor in. After emerging from the Bajoran wormhole, the Toh'Kaht was destroyed by first officer Hon-Tihl after the crew was taken over by Saltah'na energy spheres while doing the bio-survey mission. (DS9: "Dramatis Personae")