Held behind closed doors to protect the identity of the victims, the trial of Simon Moleke Njie, 34, also known as Simon Mol, is expected to last "at least a several months," defence lawyer Mikolaj Pietrzak said.
Polish police detained the suspect in January 2007 after one of his victims filed a criminal complaint against him.
Mol told investigators he had not known he was HIV positive and that he had tested negative for the virus in 1999. But Polish police investigators found that several of his partners told him they had tested positive for the disease after having had intimate relations with him.
Mol became a darling of Poland's liberal press for organising vocal campaigns against racism and supporting the cause of refugees in Poland.
The women allegedly infected by Mol range in age from 20-25. Mol is believed to have initially asked them to translate his articles and poems into Polish.
The charges carry a maximum penalty of 10 years behind bars.
Mol is also suspected of infecting two other women, currently residing outside Poland.