The effect of crude extracts from different morphological parts of Synadenium glaucescens against infectious bursal disease virus (IBDV) and fowlpox (FP) virus using an in ovo assay were investigated. Viable 9 days embryonated chicken eggs were challenged with viral strains then treated with S. glaucescens extracts at concentration of 0.2 mg/ml. Un-inoculated group were saved as negative control and groups inoculated with virus and diluent saved as positive controls. The treatments were observed daily and embryo weights were measured 5 days post-inoculation. Embryo survival and mean embryo weight were significantly higher (P ≤ 0.001) in groups treated with S. glaucescens extracts than the positive control. More than 50% of the extract prevented death and deformation of embryo and formation of pock lesions in embryos. Furthermore, the treatments with ethanolic extract of the root bark demonstrated significantly higher mean embryo weight compared to other extract for both viruses (P ≤ 0.001). The mean embryo weights from eggs challenged with infectious bursal disease virus and fowlpox virus treated with the extract were 6.3 ± 2 and 5.9 ± 0.5 g, respectively. These findings demonstrate potential and feasibility of using S. glaucescens extracts for treatment of the viral diseases. Furthermore, it validates the ethnoveterinary exploitation at community level.