Tension-type headache (TTH) is the most prevalent type of primary headache disorder. Its acute pharmacotherapy is acetaminophen or non-steroidal anti-inflammatory drugs based on the Japanese Clinical Practice Guideline for Headache Disorders 2021. With Japan's aging population, however, the number of TTH patients with comorbidities that have been treated by analgesics is increasing. Under this context, it is sometimes difficult to select an acute pharmacotherapy for TTH. Kakkonto, Japanese traditional herbal kampo medicine, is empirically used for TTH. We hypothesized that kakkonto has efficacy for TTH with painful comorbidities. We prospectively collected 10 consecutive TTH patients who had already taken analgesics for comorbidities. We prescribed 2.5g of kakkonto (TJ-1), and patients took it. A numerical rating scale for pain before and 2 hours after kakkonto intake was evaluated. Eight women and 2 men were included. The mean age was 71.0 ± 13.4 years old. Four patients had lower back pain, 2 had lumbar spinal stenosis, 2 had knee pain, 1 had neck pain, and 1 had shoulder myofasciitis. Celecoxib was used for 4 patients, acetaminophen for 3, loxoprofen for 2, and a combination of tramadol and acetaminophen for 1, as routinely used analgesics. The median numerical rating scale statistically improved from the median of 4 to that of 0. There were no side effects of kakkonto. Kakkonto showed efficacy as an acute medication for TTH with comorbidities that have been treated by analgesic.