The 22-year-old man has been charged with the murders of Michael Snee and Aidan Moffitt.
The two men were separately found dead in their homes in County Sligo on Monday and Tuesday of this week.
22-year-old Yousef Palani with an address at Markievicz Heights in Sligo was arrested on suspicion of murder hours after Mr Snee was found dead on Tuesday.
The 22-year-old faces a third charge of assault causing serious harm, arising out of an incident in Sligo on 9 April.
The accused was brought from Sligo Garda Station to the nearby courthouse in a garda van, after a number of people congregated on the 100-metre route between both buildings.
He had been questioned by detectives in Sligo since he was detained in the early hours of yesterday morning.
He was remanded in custody.