The incident occurred after the Steelers' 30-12 win over the Miami Dolphins in an AFC playoff game earlier in the day.
Based on information provided by an eyewitness, the Pittsburgh Post-Gazette reported the incident took place at about 9:30 p.m. at The Flats on Carson, a popular nightspot in Pittsburgh.
Porter refused to leave the establishment despite being asked multiple times to do so. Police were called, and a dispute developed between Porter and a police officer outside the building.
The witness told the Post-Gazette that Porter told the police officer several times, "I didn't put my hands on him."
Porter was placed in handcuffs and transported to the Allegheny County Jail. The episode lasted about 10 minutes.
Pittsburgh Police spokeswoman Sonya Toler issued a statement: "At approximately 9:30 p.m., security guards at a bar on the South Side summoned a Pittsburgh Police Officer due to an unruly customer. The customer was Pittsburgh Steelers Coach Joey Porter. He has been arrested. More information will be released later tonight."
Steelers director of communications Burt Lauten also released a statement: "We are aware of an incident tonight involving Joey Porter. We are still gathering information as it pertains to the situation, and we will have no further comment until we get more details."
Porter, in his third season on the Steelers' coaching staff, was a star linebacker for Pittsburgh from 1999-06.