This work was undertaken to determine the effect of breed and sex on some blood serum electrolytes and macro-mineral values in Sudanese sheep, and to add to the present reference values for these parameters. The blood samples were taken from two Sudanese Sheep breeds viz. Desert Sheep (56) and Nilotic Sheep (44); 52 males and 48 females. Serum level of Na, K, Ca, Mg, and P were estimated. Breed had no significant effect on the studied parameters while sex showed a significant effect on them. The overall means and range of the investigated values were calculated, compared and discussed with other researchers' results in sheep.