A selective and sensitive derivative method has been proposed for the simultaneous determination of trace amounts of Co(II) and Ni(II) with morpholinedithiocarbamate (MDTC) in the presence of sodium lauryl sulphate (SLS). The molar absorption coefficients of the 1:2 complex of Co(II) and Ni(II) at 326 nm and 322 nm are 2.248´10 4 and 2.505´10 4 L mol -1 cm -1 for zero order. The analytical sensitivity for the second derivative of Co(II) and Ni(II) complexes are 0.0044 mg mL -1 and 0.0060 mg mL -1 . The developed derivative procedure, using the zero-crossing technique, has been successfully applied for the analysis of Co(II) and Ni(II) simultaneously in different alloy samples.