The research was carried out because of a survey of wastewater treatment plant of a chemical factory, which is planned to receive dimethylamine-containing wastewater flow. It was essential to investigate the influence of dimethylamine and removal on organiс pollutants and nitrogen compounds as well as to determine the limiting concentration of dimethylamine. There were variable concentrations of dimethylamine (20-500 mg/L) under investigation in several simultaneous laboratory benches. The results showed, that dimethylamine concentration lower than 40 mg/L showed almost no impact on wastewater treatment meanwhile growth of concentration up to 300 mg/L (and above) dropped the treatment efficiency by times.