SummaryIn a population of 1 165 Large White pigs, three different serum alkaline phosphatase (Akp) types (AB 6.78 p. 100, BB 83.60 p. 100 and BC 9.62 p. 100) were found. The Akp activity of the AB type was significantly (P < 0.01) higher in comparison to the BB and BC types and the BB type had lower activity than the BC type (P < 0.05). The Zn level of the AB type was higher than those of BB and BC types (P < 0.05). The correlation between activity of Akp and Zn level in serum was highly significant (+ 0.535). The Ca level of the BC type was higher than those of the BB (P < 0.05) and AB (P < 0.01) types. On the basis of these results it is concluded that serum Akp activity and Zn and Ca levels are genetically controlled through the Akp genotype.