Objective To explore the effect of triple viable bifidobacterium lactobacillus tablets combined with polyethylene glycol 4000 on elderly patients with chronic constipation. Methods This pilot study was conducted at the Center of Gerontology and Geriatrics, West China Hospital. A total of 120 patients with chronic constipation, aged 60 years or older, treated between April 2015 and April 2016 were enrolled, and randomly assigned into group A (polyethylene glycol 4000) and group B (triple viable bifidobacterium lactobacillus tablets combined with polyethylene glycol 4000) with 60 patients in each. All the patients were estimated before and after the treatment with Bristol Stool Form Scale (BSFS), Patient Assessment of Constipation Symptom (PAC-SYM) and Constipation Related Disability (CRDS), and the adverse drug reactions were observed. Results In group A, before the treatment, the scores of BSFS, PAC-SYM and CRDS were 1.98±0.77, 37.87±4.12 and 31.03±3.19, respectively; while after the treatment, the scores were 3.87±0.82, 28.55±2.15 and 18.56±1.80, respectively, which were all significantly improved (P<0.05). In group B, before the treatment, the scores of BSFS, PAC-SYM and CRDS were 2.03±0.78, 36.25±4.98 and 30.28±3.56, respectively; while after the treatment, the scores were 4.80±0.75, 19.73±3.42 and 13.80±2.36, respectively, which were all significantly improved (P<0.05). The improvement of constipation in group B was significantly better than that in group A after treatment (P<0.05). There was no adverse drug reaction observed. Conclusion Triple viable bifidobacterium lactobacillus tablets combined with polyethylene glycol 4000 may be an effective therapy for elderly patients with chronic constipation.