Normal C strings don't support unicode, so doing QString("\u2060") will give a compiler warning saying "C4566: character represented by universal-character-name '\u2060' cannot be represented in the current code page (1252)", and will replace the \u2060 characters with question marks. Instead, it works to do: QString("Défaut suspension: Limitez votre vitesse à 90km") + QChar(0x2060) + "/" + QChar(0x2060) + "h" Or, if that's too difficult to read, this also works: QString("Défaut suspension: Limitez votre vitesse à 90km\1/\1h").replace('\1', QChar(0x2060))

[SOLVED] Eventually, the solution is to add escape character '' before any special character which has a unicode between 161 and 255 (including). E.g. "abékl" -> "ab\ékl" When looking into Qt source code and specifically to int QCssScanner_Generated::lex() (qcssscanner.cpp) one can find a huge state machine parser (css based) which expects the escape character before unicode characters 161 to 255. (the parser get called by QWidget::setStyleSheet eventually) The reason Japanese, Chinese and more non-Latin languages worked is because the state machine handles unicode characters from 256 above as is (does not expect the escape). Hope this will help others. p.s. Using QString::fromLatin1() didn't help.