Identifying neovascularity, i.e. angiogenesis, as a feature of inflammatory arthritis, can help in early diagnosis and treatment monitoring of this disease. Photoacoustic tomography (PAT), as a hybrid imaging modality, relies on intrinsic differences in the optical absorption among the tissues being imaged. Since blood has highly absorbing chromophores including both oxygenated and deoxygenated hemoglobin, PAT holds potential in identifying early angiogenesis associated with inflammatory joint diseases. In this study, we used PAT to identify the changes in the development of inflammatory arthritis, through the study on a well-established adjuvant-induced arthritis (AIA) rat model. Imaging at two different wavelengths, 1064 nm and 532 nm, revealed that there was a significant signal enhancement in the ankle joints of the arthritis affected rats when compared to the normal control group. Histological analysis of both the normal and the arthritic rats correlated well with the imaging findings. The results from this study suggest that the emerging PAT technology could become a new tool for clinical management of inflammatory joint diseases.