The copolymerization of p-acryloyloxy-tri-n-butyltin benzoate (ABTB) with acrylonitrile (AN) has been investigated in dimethylformamide (DMF), using azobisisobutyronitrile (AIBN) as an initiator. The prepared homopolymer of (ABTB), as well as the copolymers, were characterized by a variety of analytical, spectral, and thermal methods. Thermogravimetry (TG) and differential thermal analysis (DTA) data showed a little improvement in the thermal behavior of the investigated copolymer. A mechanism for the initiation of ABTB units in the nitrile oligomerization in the copolymer was also proposed.