Aims: Arthrospira platensis has been studied for single-cell protein production because of its biomass composition and its ability of growing in alternative media. This work evaluated the effects of different dilution rates (D) and urea concentrations (N₀) on A. platensis continuous culture, in terms of growth, kinetic parameters, biomass composition and nitrogen removal. Methods and results: Arthrospira platensis was continuously cultivated in a glass-made vertical column photobioreactor agitated with Rushton turbines. There were used different dilution rates (0·04–0·44 day⁻¹) and urea concentrations (0·5 and 5 mmol l⁻¹). With N₀ = 5 mmol l⁻¹, the maximum steady-state biomass concentration was1415 mg l⁻¹, achieved with D = 0·04 day⁻¹, but the highest protein content (71·9%) was obtained by applying D = 0·12 day⁻¹, attaining a protein productivity of 106·41 mg l⁻¹ day⁻¹. Nitrogen removal reached 99% on steady-state conditions. Conclusions: The best results were achieved by applying N₀ = 5 mmol l⁻¹; however, urea led to inhibitory conditions at D ≥ 0·16 day⁻¹, inducing the system wash-out. The agitation afforded satisfactory mixture and did not harm the trichomes structure. Significance and Impact of the Study: These results can enhance the basis for the continuous removal of nitrogenous wastewater pollutants using cyanobacteria, with an easily assembled photobioreactor.