The present study was undertaken to determine the pollution load to the environment causing by the wastewater effluents releasing from organized and unorganized slaughterhouses in and around Hyderabad city. The wastewater effluents collected from three slaughterhouses, at the sites of releasing out to the surrounding environment,were characterized in terms of physico-chemical and microbiological parameters. The physico-chemical parameters, such as temperature, pH, alkalinity, turbidity, total suspended solids, electrical conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand, chemical oxygen demand, total organic carbon, calcium, NH4-N, nitrates and phosphates were estimated in the wastewater effluents collected from three different slaughterhouses. The heavy metals, such as lead, nickel and cadmium contents were detected. The microbiological characteristics, such as total viable count, total coliform count recorded and also the pathogens of public health significance, such as Salmonella spp., Shigella spp., Streptococcus faecalis, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were isolated and identified. The results revealed significantly much higher values of almost all pollution parameters both physicochemical and microbiological of wastewater effluents collected from three slaughterhouses, and these values exceeding the effluent discharge standards for releasing the effluents into public sewers and inland surface waters, recommended by the pollution control board. The slaughterhouses must maintain the wastewater collection and treatment facilities and modify the existing treatment systems in order to comply the general effluents discharge standardsrecommended by the pollution control board.