A number of media components influencing a-amylase production by Aspergillus niger O103A were studied using local bitter variety of cassava (Manihotes cuelenta) as the main substrate. The media components (cassava, maltose, glucose, yeast extract, urea, NH₄NO₃, KH₂PO₄, CaCl₂, MgSO₄.7H₂O, NaCl, and FeSO₄.7H₂O) were analyzed using Plackett–Burman design. Optimal concentrations of the components contributing positively to enzyme production were further determined using one factor at a time (OFAT) and response surface methodology (RSM) method. Among different nitrogen and supplementary carbon sources tested, yeast extract 2 g/l and maltose 3 g/L were most effective for maximum production of enzyme (49 U/ml). The results show a favorable a-amylase production by applying statistical approach in optimization process.