The burning of wood in industrial activities discharge a large amount of wood ash and affecting on the environment. The effects of neem (Azadirachta indica A. Juss.) wood ash on seedling growth of cowpea (Vigna unguiculata L. Walp.) was recorded. The data reveals significant (p<0.05) effects of neem ash on the shoot length and seedling length of cowpea with the increase in the concentration of neem wood ash treatment up to 20%. The results also showed the significant (p<0.05) decrease in leaf weight ratio of cowpea as the wood ash concentration increase in substrate as compared to without ash treatment (control). The effects of neem wood ash treatment on physical and chemical characteristics of soil including organic matter (%), pH of soil, calcium carbonate (%), chloride (meq/L), maximum water holding capacity (%) of soil, electrical conductivity (mS/cm), bulk density (g/cm3), sodium and potassium content (µg/g) content of soil was found. The wood ash produced changes in physical and chemical soil characteristic viz. organic matter (%), pH of soil, water content (%), calcium carbonate (%), chloride (meq/L), maximum water holding capacity (%), electrical conductivity (mS/cm), bulk density (g/cm3), sodium and potassium content (µg/g) content of soil. Wood ash treatment affected physical and chemical poperies of soil which in turn results decreased seedling growth performance of cow pea.