Ian Thomson, 34, a farm worker and fisherman from Dumfries, was convicted of raping six former girlfriends over a nine-year-period up to 2009 after a four-week trial at the High Court in Glasgow.
Three of his victims told the court Thomson laughed after brutally raping them.
An allegation that Thomson raped one of his victims in front of her children was not proven.
A charge of raping a seventh woman in Scotstoun, Glasgow, last year was also not proven. However, he was convicted of sending her threatening text messages.
Judge John Beckett QC deferred sentence on Thomson until next month for a risk assessment and background reports. He told Thomson he had been found guilty of "many serious offences, including a number of rapes".
Thomson has previous convictions, including one for a domestic breach of the peace.