  Theoretical \emph{g}-factor calculations for the first excited \exst state of
boronlike ions in the range $Z$=10--20 are presented and compared to the
previously published values. The first-order interelectronic-interaction
contribution is evaluated within the rigorous QED approach in the effective
screening potential. The second-order contribution is considered within the
Breit approximation. The QED and nuclear recoil corrections are also taken into
account.
