Can koi live with kissing gouramis?

Verdict
Yes

Yes. Koi and kissing gouramis get along in the same tank. Both are fine at 72–77°F. Plan on at least Pond.

KoiKoi59–77°F · pH 7–8.5 Kissing gouramiKissing gourami72–82°F · pH 6–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–77°Koi 59–77°Kissing gourami 72–82°
The green band is the temperature range both can live in.
456789Both: 7–8Koi 7–8.5Kissing gourami 6–8
The green band is the pH both tolerate.

Size to scale

Koi · 24 inKissing gourami · 10 in0"6"12"18"24"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

KoiKissing gourami
Temperature59–77 °F72–82 °F
pH7–8.56–8
Adult size24.0 in10.0 in
Minimum tankPond55 gal
TemperamentPeacefulSemi-aggressive
Swims atAll levelsMiddle
GroupGroups of 3+Alone or in pairs
DietOmnivoreOmnivore

Better tank mates for koi

All koi tank mates

Better tank mates for kissing gouramis

All kissing gourami tank mates

Questions

Can koi live with kissing gouramis?

Yes. Koi and kissing gouramis get along in the same tank. Both are fine at 72–77°F. Plan on at least Pond.

What temperature suits both koi and kissing gouramis?

72–77 °F. Koi need 59–77 °F, kissing gouramis need 72–82 °F.

What size tank do koi and kissing gouramis need together?

A pond. Koi outgrow indoor tanks.