The market at Porta Portese is a major flea market in Rome and is held every Sunday until around 1pm. At this market you will find second hand clothing, furniture, coins, books and many more miscellaneous items. The market at Porta Portese tends to be very crowded so keep a close eye on your belonging as thieves are known to frequent the market as well.
The main strip in very long and narrow filled with people. To be honest, it was a bit much pushing your way through. I was really disappointed with the selection. But after the long casino (casino means mess in Italian), I found some interesting vintage items. I liked the old hardware, nails, hats and other found objects. They also had a small but nice selection of vintage furniture, frames and mirrors.