A rapid and simple procedure was established to obtain clonal axenic cultures of Tetratrichomonas gallinarum and Trichomonas gallinae and to optimize their in vitro growth conditions. Medium 199 was used for axenization of two genetically different clones of T. gallinarum and T. gallinae. Six different media were used to optimize the growth behaviour of axenically grown parasites: Medium 199, TYM, TYI-S-33, Hollander fluid (HF), Trichomonas vaginalis (TV) and odified TV media. The highest cell yields for both axenic clones of T. gallinarum were obtained in modified TV medium without antibiotics. The maximum numbers of trophozoites of T. gallinae were obtained in an optimized HF medium. This study demonstrated that axenic cultures for T. gallinarum and T. gallinae could be obtained avoiding the migration technique through a V-tube. Following axenization and optimization, both clones of T. gallinarum and T. gallinae could be propagated both aerobically and anaerobically.