Can upside down catfish live with kissing gouramis?

Verdict
Yes

Yes. Upside down catfish and kissing gouramis get along in the same tank. Both are fine at 72–79°F. Plan on at least 55 gal.

Upside down catfishUpside down catfish72–79°F · pH 6–7.5 Kissing gouramiKissing gourami72–82°F · pH 6–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–79°Upside down catfish 72–79°Kissing gourami 72–82°
The green band is the temperature range both can live in.
456789Both: 6–7.5Upside down catfish 6–7.5Kissing gourami 6–8
The green band is the pH both tolerate.

Size to scale

Upside down catfish · 4 inKissing gourami · 10 in0"2"4"6"8"10"
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

Upside down catfishKissing gourami
Temperature72–79 °F72–82 °F
pH6–7.56–8
Adult size4.0 in10.0 in
Minimum tank30 gal55 gal
TemperamentPeacefulSemi-aggressive
Swims atBottomMiddle
GroupGroups of 3+Alone or in pairs
DietOmnivoreOmnivore

Better tank mates for upside down catfish

All upside down catfish tank mates

Better tank mates for kissing gouramis

All kissing gourami tank mates

Questions

Can upside down catfish live with kissing gouramis?

Yes. Upside down catfish and kissing gouramis get along in the same tank. Both are fine at 72–79°F. Plan on at least 55 gal.

What temperature suits both upside down catfish and kissing gouramis?

72–79 °F. Upside down catfish need 72–79 °F, kissing gouramis need 72–82 °F.

What size tank do upside down catfish and kissing gouramis need together?

At least 55 gal, set by the kissing gourami. Add space for each extra fish.