I want to use
Enable word wrapping by calling
void setWordWrap ( bool on )
and set text elide mode to Qt::ElideNone
void setTextElideMode ( Qt::TextElideMode mode )
Also you may check that you didn't set too small maximum height for your items in the list.
P.S. Because you wrote about horizontal scrollbar, you definitely want to have multiline text in item, but not the item on multiple rows.