The present study was conducted to evaluate the effect of parenteral supplementation of cobalt, copper and iron in late pregnancy on ewe hematology parameters and lamb vigour. Twenty ewes were allocated to one of two groups (n=10). In the test group, on day 120 of pregnancy, cobalt, copper and iron were injected at a dose of 0.1 mL/kg BW (Fercobsang, France, cobalt gluconate 5 mg/100 mL, copper gluconate 0.5 mg/100 mL and ferrous citrate 1000 mg/100 mL). Ewes in the control group received equal amounts of normal saline as placebo. Group had no significant effect on ewe hematological parameters (P>0.05). There were no significant effects of parenteral mineral supplementation on lamb birth weight, rectal temperature and weaning weight after birth. Lamb viabilities are reported as scores as these gave a true representation of the effects of treatment on underlying measurements. However, there were no differences between groups in lamb vigour and sucking assistance score. It seems that using of additional trace elements in late pregnancy could be effective only in deficiency situations.