ZnO-ZrO₂ nanocomposites using zinc (II) acetylacetonate and different ZnO contents (13, 25, 50, and 75% mol) were synthesized through sol-gel method. The synthesis process was strongly related to nanocomposite properties especially on their structural composition. The obtained ZnO-ZrO₂ nanomaterials presented tetragonal crystalline structure for zirconia whereas hexagonal one was formed in ZnO. Raman spectroscopy and XRD patterns confirmed the formation of tetragonal zirconia whereas inhibition of monoclinic structure was observed. Addition of ZnO affected the pore size distribution of the composite, and the measured specific surface areas were from 10 m²/g (for pure ZnO) to 46 m²/g (pristine ZrO₂). Eg values of ZrO₂ were modified by ZnO addition, since calculated values using Kubelka-Munk’s function varied from 4.73 to 3.76 eV. The morphology and size of the nanomaterials investigated by electron microscopy showed formation of nanorods for ZnO with sizes ranging from 50 nm to 300 nm while zirconia was formed by smaller particles (less than 50 nm). The main advantage of using the nanocomposite for photocatalytic degradation of phenol was the mineralization degree, since 75ZnO-ZrO₂ nanocomposite surpassed mineralization reached by pure ZnO and also inhibited formation of undesirable intermediates.