In-situ polymerization of methyl methacrylate (MMA) was carried out in the presence of various concentrations of cobalt II nitrate (Co(NO3)2) to synthesize poly (methyl methacrylate) (PMMA)/ Co(NO3)2 complexes by a free radical polymerization method. The polymer metal complexes were characterized by employing UV–visible absorption and Fourier transform infrared spectroscopy. The surface morphology of the complexes was analysed with scanning electron microscopy. Thermal stability and glass transition temperature of the complexes was determined by thermal gravimetric analysis and differential thermal analysis respectively. AC conductivity behaviour was investigated in the frequency range of 100- 106 Hz at room temperature. The UV and FTIR spectra confirmed the co-ordination interaction between PMMA and Co(NO3)2. SEM images showed that the metal oxide particles were well dispersed in the macromolecular chain of PMMA. Thermal studies showed that the thermal stability and glass transition temperature of the samples were increased with increase in Co (NO3)2 concentration in PMMA. AC conductivity was significantly higher than pure PMMA and the conductivity increased with increase in Co Co(NO3)2 content and also with the increase in frequency.