Eight viruses were isolated in embryonating eggs, from psittacine birds comprising a cockatiel, a budgerigar, 3 parrots, a love bird, and 2 rosellas. Initial attempts at isolation used 3 routes of embryo inoculation: yolk sac, allantoic sac, and chorioallantoic membrane (CAM). The most sensitive route was determined for 6 of the isolates by making comparative titrations by yolk sac, allantoic sac, and CAM routes of inoculation. In growth-curve studies of 6 of the isolates, virus concentration was determined daily for 5-6 days postinoculation in the CAM, allantoamnionic fluid, and liver. Peak virus concentrations appeared in about 72 hours. The embryonic lesions observed are described. Only one of the isolates hemagglutinated fowl red blood cells.