The effects of immunomodulatory treatment with levamisole oil uterine involution, ovarian function and total sialic acid (TSA) concentrations during postpartum period in lactating dairy cows were investigated. In Group I (n=20), levamisole hydrochloride (Actipar (R)) was weekly administered at immunomodulating doses (2.5 mg/kg; IM) starting from five or six weeks until two weeks prior to expected calving. In Group II (n=13), physiologic saline was administered during the same injection schedule. All cows (n=33) were examined oil days 16 +/- 3, 23 +/- 3, 30 +/- 3 and 37 +/- 3 postpartum including external inspection, vaginoscopy, and transrectal ultrasonography. Relative risk of cows in control group having a pathological vaginal discharge (7/11; 63.6%) was 1.9 (0.8-4.4; P>0.05) times higher than that in levamisole treated group (5/15; 33.3%). There is an interaction effect of treatment by vaginal discharge scores on the involution of cervix uteri (P<0.05), and levamisole treatment accelerated the involution of the cervix uteri in cows with normal vaginal discharges compared to those with pathological discharges. There was an earlier recruitment of the follicular wave in cows with normal vaginal discharge compared to those with pathological vaginal discharge. Serum TSA concentrations were higher in cows with pathological vaginal discharge than those with normal vaginal discharge (P<0.01). Consequently, facilitation of involution of the cervix uteri and earlier recruitment of the follicular wave in cows with normal vaginal discharge reveals beneficial effect of immunomodulatory treatment with levamisole, and warrants further research regarding the immunomodulatory treatment with levamisole during dry period prior to breeding protocols. In addition, relationships between vaginal discharge scores and TSA concentrations could be used for evalulation of postpartum reproductive health.