The effectiveness of tiletamine–zolazepam (Telazol) and xylazine as an immobilizing combination for American martens (Martes americana) was evaluated. Fifteen martens were intramuscularly injected on 19 occasions using a 3:2 mixture of tiletamine–zolazepam (3.2±0.6 mg/kg [mean ± SD]) and xylazine (2.1 ±0.4 mg/kg) at Pictured Rocks National Lakeshore, Michigan (USA) during May to October 2002–2003. Mean induction time was 2.5 ±1.8 min; mean recovery time was 70.8±31.9 min. There was no relation between the amount (mg/kg) of tiletamine–zolazepam–xylazine injected and induction (r²=0.08, P = 0.26). However, there was an inverse relation (r²=0.28, P<0.01) between dosage and time to first effect of immobilants. Time to recovery increased (r=0.21, P=0.05) with increased dosage. Mean heart rate, respiratory rate, and body temperature declined through 10 min postinduction (P<0.05). No mortality occurred and no short-term adverse effects were observed in recaptured individuals. In conclusion, a 3:2 mixture of tiletamine–zolazepam/xylazine is a safe and effective immobilizing agent for martens when conducting nonsurgical field procedures. Immobilizing martens with 4.2 mg/kg tiletamine–zolazepam and 2.8 mg/kg xylazine should provide ≤30 min of handling time and allow full recovery in about 70 min.