Despite the increase in guava growing area, improvement in postharvest quality is still negligible. The influence of putrescine (PUT), hydroxypropyl methylcellulose (HPMC) and their combinations on postharvest life and fruit quality of ‘Maamoura' guavas was evaluated for two consecutive seasons (2016 and 2017). The experiment included six postharvest treatments; distilled water (control), 1 mM PUT, 2 mM PUT, 5% HPMC, 1 mM PUT incorporated with 5% HPMC and 2 mM PUT incorporated with 5% HPMC. These treatments were performed by immersing guava fruits for five minutes.  Treated and control fruits were stored at 7±1°C and 90±5% relative humidity (RH) for 24 days. The changes in physical and chemical characteristics of guava fruits were determined every eight days of cold storage. Results of this study indicated that, all postharvest treatments of ‘Maamoura' guavas reduced the deterioration in physical and chemical characteristics as compared to untreated fruits (control). In addition, combined treatments of PUT at 1 or 2 mM and 5% HPMC were superior than individual treatments. These treatments significantly minimized physiological loss in weight, reduced decay incidence and maximized marketable percentage as well as maintained fruit firmness and visual appearance score during storage. Moreover, these applications significantly delayed colour development by retained total chlorophyll content as well as significantly maintained fruit contents in ascorbic acid and titratable acidity and also significantly slowed the accumulation of fruit contents in total soluble solids and total soluble solids/titratable acidity ratio during cold storage period. Ultimately, these applications significantly prolonged the shelf life period for guavas at ambient conditions (25±2°C and 65±5% RH) after the end of cold storage period (24 days) as compared to control. In particular, postharvest application of PUT at 2 mM incorporated with 5% HPMC of guavas was the most effective in this aspect than the other treatments and control. Therefore, this application is a promising method for alleviating decay, preserving quality and extending postharvest life period of ‘Maamoura' guava fruits during cold storage.