<b><i>Introduction:</i></b> Prevention of attacks is a major goal in management of patients with hereditary angioedema (HAE). We aimed to investigate the effects of a systematic intervention for HAE patients. <b><i>Methods:</i></b> Thirty-three patients with HAE with C1-inhibitor deficiency, belonging to a single family, participated in a management program coordinated by an allergist/immunologist. Angioedema attacks before intervention were ascertained by interviews and emergency room charts and recorded prospectively by patients or caregivers after enrollment. Mean number of attacks/month was compared at 12 months preintervention and 8 and 14 months within intervention. Patient-reported outcome instruments were used to assess quality of life, including HAE Quality of Life (HAE-QoL) questionnaire, psychological conditions, and work impairment, at baseline and 8 and 14 months within intervention. Data were stored in REDCap platform and analyzed by adjusted Bayesian models of double Poisson regression. <b><i>Results:</i></b> Mean number of attacks/month significantly decreased (95% credible interval [CrI] excluding 0) from 1.15 preintervention to 0.25 and 0.23, 8 and 14 months within intervention, with mean decreases of −0.89 (95% CrI: −1.21 to −0.58) and −0.92 (95% CrI: −1.22 to −0.60), respectively. HAE-QoL scores showed mean total increases of 15.2 (95% CrI: 1.23–29.77) and 26 (95% CrI: 14.56–39.02) at 8 and 14 months within the study, as compared to baseline, revealing marked improvement in quality of life. Significant increase in role-emotional and reduction of depression, stress, and anxiety were observed at 14 months. <b><i>Conclusion:</i></b> A systematic approach integrating HAE-specific care with effective handling of psychological issues decreased the number of attacks and improved quality of life, targets for best practice in HAE.