Prostate gland can be structurally evaluated by computed tomography (CT) with taking advantages of tomographic feature and post-contrast parenchymal changes. The current examination initiated to determine association between computed tomographic and cytological results in evaluation of canine prostate. Thirty mature male dogs were included and under gone by both CT and fine needle sampling of prostate. The cytology and CT examination results showed 18/30 (60.00%) and 15/30 (50.00%) normal prostate, 5/30 (16.66%) and 4/30 (13.33%) prostatitis and 7/30 (23.33%) and 11/30 (36.66%) benign prostatic hyperplasia, respectively. Moderate agreement has been found between cytology and final diagnosis based on pre-contrast CT images, however fair agreement was existed between cytological diagnosis and final CT interpretation according to post-contrast and both pre- and post- contrast CT series. Additionally, the internal iliac lymph node length showed statistically significant difference in prostatitis compared to normal and benign hyperplastic prostates in this study. In conclusion, the fair and moderate associations between cytology and final diagnosis based on CT images should be considered and they can be used in further investigations and clinical examinations. Also, using internal iliac lymph node length to differentiate prostatitis with normal and benign hyperplastic prostates can be used efficiently in diagnosis to choose the best method of management and have a proper follow up and prognosis.