BACKGROUND: Mastitis could be detected in various ways, including physical, on-farm, and laboratory tests. OBJECTIVES: The present research aimed to evaluate the accuracy of the diagnosis of mastitis using lactate dehydrogenase (LDH)-based dipsticks and to assess these dipsticks with regard to the effects of different lactation days, the amount of milk production, and parity. RESULTS: Considering bacteriologic culture as a gold standard method for the diagnosis of subclinical mastitis, the sensitivity and specificity of LDH test were 68.9 % and 54 %, respectively. The results revealed a high correlation between SCC and LDH. A statistically significant relationship was observed between the response of dipstick and CMT results; with the increase in the CMT score, the score of LDH dipstick increased. By investigating the effects of lactation days, the amount of milk production, and parity, it was determined that the chance of having subclinical mastitis in cows with positive dipstick result was 5.59 times greater than that in cows with negative dipstick result. There were no significant relationships among SCC, LDH, and CMT with lactation days and milk production; meanwhile, with the increase in parity, the three above-mentioned variables showed significant increase. CONCLUSIONS: The results of the present study indicated that the best methods for subclinical mastitis detection were SCC, CMT, and LDH based dipsticks, respectively.