A theoretical formalism has been developed for forbidden radiative processes with Delta S=+/-1 in small homonuclear diatomic molecules. Spin-dependent electric multipole and magnetic multipole operators which are responsible for spin-forbidden radiative transitions are expressed as tensor operators and forbidden transition probabilities are worked out by using Racah Algebra. Spin-dependent electric dipole (SE1) and magnetic quadrupole (SM2) interactions are assumed to connect two states of different spin multiplicities as well as different inversion symmetry whereas spin-dependent electric quadrupole (SE2) and magnetic dipole (SMI) interactions are assumed to connect two states of the same inversion symmetry but of different spin multiplicities. Transition probabilities are presented for a few forbidden radiative transitions with Delta S=+/-1 between states having different symmetry as well as having the same symmetry.