A picket line formed outside Darwen Vale High School during a 24-hour shutdown this morning.
Teaching unions said members felt the school was "out of control" and management had failed to back them in attempts to deal with discipline.
Unions have received several complaints from members including pushing, shoving and swearing at teachers and some pupils filming staff on mobile phones and clips being posted on Facebook.
Members of the National Union of Teachers (NUT) and National Association of Schoolmasters/Union of Women Teachers (NASUWT) voted overwhelmingly to take one-day strike action.
National executive member for the NUT Simon Jones said: "Members are taking strike action as a last resort because of the headteacher's continued denials that there is a problem with pupil behaviour in the school and her refusal to engage properly with staff and unions to find effective solutions to these challenges.
"Staff and unions have been raising concerns for the last two terms but the head has rejected repeated requests for earlier meetings to try to resolve this dispute informally.
"We regret that this industrial action is necessary and recognise that it will affect pupils' education for a day." Read More