A selective medium (CGT medium), containing clindamycin, gentamicin, potassium tellurite and amphotericin B in 5% horse-blood agar, allowed unimpaired growth of almost all strains of Pasteurella multocida, and P pneumotropica, while inhibiting other bacteria that might be encountered in upper respiratory tract secretions. With its use, P multocida was readily detected in oral swabs from four of 23 dogs, and 10 of 25 cats, but not detected in oral swabs from 47 human subjects. One of 500 sputum specimens yielded P pneumotropica.