Objective To observe the effect and adverse reactions of flupentixol/melitracen combined with lactulose on constipation and anxiety status in the elderly constipated patients with mild to moderate anxiety. Methods Eighty elderly constipated out-patients [aged (74.6±7.6) years] suffering from mild to moderate anxiety in our department from January 2011 to December 2012 were recruited in this study. They were randomly divided into treatment group and control group. The patients in treatment group were treated with flupenthixol melitracen tablets 1qd, and lactulose 15ml bid, while the patients in control group were given lactulose 15ml bid only. The regimen of treatment lasted for 4 weeks in both groups. The effective rate and self-rating anxiety scale (SAS) score was measured and recorded at the 2nd and 4th weeks after treatment. Results The constipation symptoms were alleviated in the 2 groups at the end of treatment. The total effective rate after 2 weeks treatment was significantly higher in the treatment group than in control group (P＝0.029). The SAS scores were decreased more significantly in the treatment group than in the control group at the 2nd and 4th week (P＝0.020, P＝0.012). No serious adverse reaction was found in the 2 groups of patients. The incidence of adverse reactions had no statistical difference between the 2 groups (P＞0.05). Conclusion Flupentixol/melitracen combined with lactulose is effective and safe in the treatment of functional constipation in the elderly patients with mild to moderate anxiety.