A flotation method for simultaneous separation of cobalt and nickel traces from fresh water is proposed. Lead(II) hexamethylenedithiocarbamate, Pb(HMDTC)(2), was used as a new collector for the precipitate flotation preconcentration. It was obtained during the reaction between hexamethyleneammonium-hexamethylenedithiocarbamate. HMA-HMDTC, and lead(II) ions. Mass of lead, m(Pb), amount of hexamethylenedithiocarbamate, n(HMDTC-), pH of the system, induction time, type of surfactants, which are all important parameters for the successful flotation, were studied and optimized. After flotation preconcentration. electrothermal atomic absorption spectrometry (ETAAS) was applied for cobalt and nickel determination. The results obtained by ETAAS were compared with the results obtained by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The detection limit of the proposed method is 0.025 mug/L for cobalt and 0.0157 mug/L for nickel.