Obesity is said to be one of the exacerbating factors of chronic pain, however its mechanism is unclear. Recently, fatty acid binding protein 3 (FABP3) functions as not only an intracellular chaperone to transport fatty acids, but also the signal transduction and gene transcription. There are some recent reports that FABP3 is induced in response to an increased dietary fat load as well as obesity, inflammation and pain. Here we tested whether FABP3 involve in the mechanism for obesity-induced exacerbation of postoperative pain using FABP3 deficit (FABP3KO) mice. Male ddY and C57BL6J wild-type (WT) mice were used by experiment. WT and FABP3 KO were fed on control diet or high fat diet (HFD) for 8 weeks. Postoperative pain was induced by paw incision. Mechanical allodynia was evaluated by von Frey test. Mice with paw incision showed mechanical allodynia. Repeated intracerebroventricully injection of FABP-IN-1, a FABP inhibitor for FABP3, 5 and 7, suppressed paw incision-induced mechanical allodynia. The mice fed HF diet exacerbated paw incision-induced mechanical allodynia compared to those in control diet fed WT mice. On the other hand, FABP3KO mice fed HF diet suppressed paw incision-induced mechanical allodynia. Our findings suggest that FABP3 might at least in part involve in obesity-induced exacerbation of postoperative pain.