The stellate ganglion block (SGB) procedure has been used successfully for over twelve years to treat thousands of patients suffering from posttraumatic stress disorder (PTSD). Level 1b evidence supports this use of SGB, but no studies to date have reported specifically on anxiety symptom improvements following SGB. We collected Generalized Anxiety Disorder questionnaire (GAD-7) scores pre-procedure and at 1-week and 1-month post-procedure from 285 patients. The mean baseline GAD-7 score of 15.9 (indicating severe anxiety) declined significantly following SGB treatment. Changes in GAD-7 scores ≥ 4 were considered clinically meaningful. From baseline to 1 week, the GAD-7 scores dropped by 9.0 points (95% CI = 8.3–9.7,p< 0.001, d = 1.8), with 211 (79.6%) patients demonstrating clinically meaningful improvement. Furthermore, from baseline to 1 month, the GAD-7 scores dropped by 8.3 points (95% CI = 7.6–9.0,p< 0.001, d = 1.7), with 200 (75.5%) patients demonstrating clinically meaningful improvement. The stellate ganglion block treatment resulted in a decrease of GAD-7 scores of over twice the minimal clinically important difference in treating anxiety for at least 1 month following SGB. Given the results from this retrospective observational study, larger prospective studies should be conducted to determine the effects of SGB treatment as a novel therapeutic treatment for generalized anxiety disorder and other anxiety disorders.