BACKGROUND: Light attenuation in a photobioreactor is an inevitable phenomenon, which creates a heterogeneous radiation field inside the culture. However, few investigations have been carried out on the modeling of periodic light during cyanobacterial cell growth, despite the strong effect of the attenuating light irradiance on cell growth kinetics. The purpose of this work is to analyze the available growth models (Monod, Aiba-Edwards and Haldane) and to then develop a model that incorporates light attenuation phenomenon. RESULTS: The inhibitory Haldane model was found to be the best model to represent the current experimental data with mu(max), K-sl and K-il selected as 0.25 h(-1), 190 mu E m(-2) s(-1) and 850 mu E m(-2) s(-1), respectively. A new light attenuation model was successfully developed by establishing the relationship between the attenuated light irradiance and the cell concentration. It is applicable to a broad range of light irradiances from 25 to 910 mu E m(-2) s(-1). CONCLUSION: Light inhibition and attenuation imposed significant effects on cyanobacterial growth. The newly developed light attenuation model offers various possible future applications, which include automatic monitoring of the instantaneous cell concentration without the need for manual sampling, and effective optimization of the specific irradiation rate in indoor cultures. (C) 2016 Society of Chemical Industry