Belgium's "trial of the century" has gripped the country since 1995, when the girls were abducted by Dutroux and imprisoned in an underground cell.
The jury found the unemployed electrician guilty of murdering 17-year-old An Marchal and 19-year Eefje Lambrecks, along with former accomplice Bernard Weinstein.
After a three-month trial in Arlon, the jury also found the accused guilty of kidnapping two 8-year-old girls -- Julie Lejeune and Melissa Russo -- who died while Dutroux was in prison. Two other abducted girls were rescued in August 1996.
Dutroux, 47, arguably the most hated man in Belgium, could be sentenced to life imprisonment for his crimes, which include leading a kidnap gang. Several of Dutroux's accomplices have been convicted of helping to abduct the girls.