Among the existing biofuels, bioethanol is expected to be the most widely used one around the globe. The production of bioethanol with current processes can address several issues, such as its impact on food supply and security for 1st generation technologies and the high costs involved in the hydrolysis step of 2nd generation technologies. The utilization of microalgae for 3rd generation bioethanol is a promising alternative to the production of the fuel, since it may overcome some of the drawbacks found in the production of both 1st and 2nd generation bioethanol. In this context, this work aims to evaluate the growth kinetics and the influence of pH and dissolved O2 and CO2 on the cultivation of the green microalga Chlorella vulgaris in a flat-plate photobioreactor. Three different variables were studied on a central composite design: PAR (photosynthetically active radiation) light flux between 60 and 120 μE s-1 m-2, CO2 supplementation in the gaseous feed (from 0 to 12%) and nitrogen concentration in the culture medium (between 156 and 2300 g L-1). Within seven days of cultivation, stationary growth phase was not reached under any condition and exponential growth phase on all cultivations remained until the last days of the experiments. Rise of pH and dissolved O2 levels due to photosynthetic activity were also observed. Biomass productivity was significantly affected by both light flux and CO2 content in the gas stream and productivities as high as 0,262 mg L-1 day-1 were achieved.