Different clinical conditions have been associated with the presence of pain in animals, so understanding the pathophysiological changes associated with their response is essential in in-hospital clinical monitoring. The objective of this study was to describe the usefulness of facial thermography in the recognition of acute pain in hospitalized cats (Felis catus), for which 71 cats were studied with an average weight of 4.3±1.4 Kg and an age average of 4.4±3.5 years. Facial temperature values were obtained in different region of interest (ROI) and compared according to the values of the Grimace pain scale in cats according to the following subclassification: Group 1, control animals (n=10); Group 2, animals classified with score 0-3 (n=21); Group 3, animals classified with score 4-6 (n=30) and Group 4, animals classified with score 7-10 (n=10). The global average temperature of the facial (F), auricular (A), periocular (PO), nasal (N) and rectal (R) regions was 33.7±1.9; 31.4±3.6; 32.1±0.9; 28.9±4.5 and 38.3±0.8 oC respectively. A difference (p<0.05) was observed between the temperature of A and PO as well as between PO and N, but not between A and N. The present study allowed us to show an increase (p=0.0484) in the temperature mean PO ROI in G4 animals compared to G1 and a correlation with R temperature and peak temperature in the PO region in all groups. It is concluded that the increase in temperature of the periocular region and the nasal plane observed through infrared thermal imaging of the facial surface of hospitalized cats suggests the presence of clinically relevant acute pain. Facial thermography is a safe and non-invasive diagnostic method that complements other methods of identifying pain in cats.