The micro-scale adhesive contact behavior of a spherical rigid punch on a piezoelectric half-space is investigated in this paper. The governing equations describing the adhesive contact behavior are obtained by using the Maugis-Dugdale (M-D) elastic adhesive contact theory [J. Colloid Interface Sci. 150 (1992) 243]. The solutions for indentation of piezoelectric materials and for elastic adhesive contact can be reduced from the present results in the absence of adhesion effect and piezoelectric effect, respectively. The effect of the electric load on the adhesive contact behavior is analyzed. It is shown that the piezoelectric effect has a significant effect on the adhesive contact behavior of piezoelectric materials. The obtained results will be helpful to understand the micro-indentation properties of piezoelectric materials.