We employed density functional theory (DFT) in order to study the structural, electronic, and magnetic properties of pure AlN and C-atom-doped AlN compounds. The calculations were carried out using the method based on pseudopotential, employed exactly as implemented in Quantum ESPRESSO code. For the description of the electron–electron interaction, generalized gradient approximation (GGA) was used. The calculations showed that the substitution of a C atom at the N site introduce a magnetic moment of about 1.0 μB, while two C atom substitutions introduce a magnetic moment of about 2.0 μB. These magnetic properties become hybridization states C-2p and their first neighboring Al-2p and first neighboring N-2p atoms. Calculated magnetic properties indicate that C-doped AlN compound can potentially be used in diluted magnetic semiconductors.