The use of midazolam as a tranquilizer for anesthesia in mustelids in conjunction with the cyclohexamine ketamine is not well documented. Because midazolam is fast acting, inexpensive, and quickly metabolized, it may serve as a good alternative to other more commonly used tranquilizers. We trapped and anesthetized 27 Pacific martens (Martes caurina) in Lassen National Forest (northern California, US) August 2010–April 2013. We assessed anesthesia with ketamine at 18 and 25 mg/kg combined with 0.2 mg/kg of midazolam by comparing mean times of induction, return to consciousness, and recovery, plus physiologic parameters. No reversal was used for the midazolam portion of the anesthetic. Mean (±SD) induction for both ketamine dosages was 1.7±0.5 and 1.8±1.0 min, respectively. Return to consciousness mean times were 8.0 min longer (P<0.001) for martens receiving a 25 mg/kg ketamine dosage. Mean recoveries were 15.1 min longer (P<0.003) for the 25 mg/kg ketamine dosage. Physiologic parameter means were similar for both ketamine dosages with no statistically significant differences. Body temperatures and heart and respiratory rates were generally stable, but percentage of oxygen saturation and end tidal carbon dioxide values were below those seen in previous mustelid studies. The combination of ketamine, at both dosages, and midazolam provided reliable field anesthesia for Pacific martens, and supplemental oxygen is recommended as needed.