Commercial Leghorns vaccinated with F strain Mycoplasma gallisepticum were used to determine the effect of hydration of swab material with Frey's broth media on M. gallisepticum isolation. Twenty-four hens from each of four 10,000 bird houses were randomly selected and swabbed from the choanal cleft region. Twelve birds from each house were swabbed with ethylene-oxide-sterilized, 2.4-mm diameter rayon-tipped swabs, and 12 hens were swabbed with the same type swabs wetted with sterile Frey's broth media. Results of the present study demonstrate that wetting of the swab prior to swabbing does not affect the recovery of M. gallisepticum from commercial layers.