Environmental impact assessment of ten (10) effluents from pharmaceutical industries in Lagos (4), Ogun (2) and Kwara (4) states in Nigeria was carried out in this study. Five freshwater tadpoles of fairly similar sizes were exposed to each of the effluent for 5 days. The physicochemical parameters, nutrient and heavy metals composition of the effluents were also evaluated using standard methods. After 5 days of observation, the mortality rate of the tadpoles ranged from 60% to 100% with all of Kwara effluents resulting in 100% mortality. Also, the positive control (tadpoles + fresh water) and negative control (tadpoles + laboratory tap water) had no mortality and 20% mortality rate respectively. The mean pH ranges (4.84 to 6.46), turbidity value (17.58 - 96.40 NTU), total dissolved solids (25.80 to 860.26 mg/L) and conductivity (28.50 to 205.0 cm/s2) of the effluents were outside the minimum acceptable range of the regulatory agencies. The dissolved nutrients, Chemical Oxygen Demand (COD), Dissolved Oxygen (DO) were also within regulatory limits except for nitrite and sulfide ion while the alkalinity of some samples exceeded the acceptable range. The organic compounds as well as the heavy metal concentrations were also within the stipulated limits, except Zinc and Magnesium.