We report on a search for the X(1812) state in the decay B-+/--> K-+/-omega phi with a data sample of 657x10(6) BB pairs collected with the Belle detector at the KEKB e(+)e(-) collider. No significant signal is observed. An upper limit B(B-+/-->(KX)-X-+/-(1812),X(1812)->omega phi)< 3.2x10(-7) (90% C.L.) is determined. We also constrain the three-body decay branching fraction to be B(B-+/--> K-+/-omega phi)< 1.9x10(-6) (90% C.L.).