This double-blind, placebo-controlled study assessed the efficacy of 4 weeks of impulse magnetic-field therapy (16 Hz, 5 microTs), delivered through a small device, for different types of headache and migraine. Eighty-two patients were randomly assigned to receive either active treatment or placebo (n = 41 each) and were characterized according to one of seven diagnoses (migraine, migraine combined with tension, tension, cluster, weather-related, posttraumatic, or other). Efficacy was assessed in terms of duration, severity, and frequency of migraine and headache attacks, as well as ability to concentrate. Data for 77 patients were analyzed. In the active-treatment group, all assessed criteria were significantly improved at the end of the study (P < .0001 vs baseline and placebo). Seventy-six percent of active-treatment patients experienced clear or very clear relief of their complaints. Only 1 placebo-patient (2.5%) felt some relief; 8% noted slight and 2% reported significant worsening of symptoms. No side effects were noted.