In a trial for comparison between the efficiency of single fowl pox (FP) vaccination and the efficiency of each combined FP and Avian encephalomyelitis (AE) vaccination and simultaneous vaccination with FP and Reo and with FP and Chicken anemia virus (CAV) vaccines our conclusion was that there is no antagonistic reaction between FP virus strain and each AE, Reo and CA viruses strains. In addition, humoral immune response against AE virus strain in case of combined AE+FP vaccination is markedly potent than that in case of single AE vaccination, more over the value of average EID50 of AE virus strain in several batches of combined AE+FP vaccines is significantly higher at P > 0.05 than that in several batches of single AE vaccines. On the other hand, immune response against FP virus strain and Reo virus strain in case of simultaneous vaccination with FP and Reo vaccines is higher than that in case of single FP vaccination and single Reo vaccination. Consequently, it is advisable to use combined live attenuated AE+FP vaccine instead of vaccination with single FP and AE separately. Also, application of simultaneous vaccination with FP and Reo vaccines is advisable as it is proved to be more beneficial than vaccination with each vaccine separately specially in case of that FP vaccine of low potency.