Here, we examine the structural, vibrational, optical, and morphological properties of ZnO particles synthesized by the hydrothermal method, incorporating cadmium at different concentrations through the molar ratio Rm = Cd+2/Zn+2 and a thermal treatment at 500°C. The X‐ray diffraction results demonstrated the high crystallinity of the ZnO compound with a wurtzite‐type hexagonal structure. The Raman scattering spectra demonstrated that the ZnO vibrational modes occur in the region between 200 and 1300 cm−1, which is associated with different vibrational configurations characteristic of the ZnO molecule: E2(Low), E2(M), A1(TO) E1(TO), 2B1(High), E2(High), and TA + LO. The modes that were most affected by the incorporation of Cd2+ were those assigned to 2E2(Low), E2(M), and 2B1(High), and this effect was associated with a greater displacement of Zn2+ ions. The optical study showed a reduction in the band gap and a decrease in the crystalline quality due to the substitution of Cd2+ in the ZnO lattice. Cadmium incorporation affected the morphology of the ZnO:Cd particles, changing the lengths and diameters of the ZnO rods; when the Cd concentration was increased, the ZnO rods shortened, forming coin‐type hexagonal structures.