The aim of this study was to develop sago starch-based bionanocomposite films containing TiO2 nanoparticles and Penganum harmala extract (PE) to increase the shelf life of chicken fillets. First, sago starch films containing different levels of TiO2 nanoparticles (1, 3 and 5%) and PE (5, 10 and 15%) were prepared, and the thickness, barrier properties, and antibacterial activity of the films. Then, the produced films were used for the chicken fillets packaging and the physicochemical and antimicrobial properties of samples were examined during 12-day storage at 4°C. The results showed that the addition of the combination of nanoparticles and extract and increasing their levels in the films increased the antibacterial activity against gram-positive and gram-negative bacteria. The results also demonstrated that during the storage period, the pH, total volatile basic nitrogen (TVB-N), and the number of aerobic mesophilic bacteria, psychrophilic bacteria, coliforms, molds and yeasts in fillets increased (p<0.05). However, coating the fillets with bionanocomposites can significantly reduce the rate of change in chemical properties and microbial growth of the samples. This sample increased the shelf life of the fillets by at least 8 days compared to the control sample.