The purpose of this note is to prove some theorems on set theoretic complete intersections in Stein manifolds (or Stein spaces) which are analogous to results in affine algebraic geometry. Due to the Oka principle in Stein theory one gets stronger results. For example any locally complete intersection Y of dimension ≦3 in a Stein space X with dim X>2 dim Y is a set theoretic6 complete intersection. A 4-dimensional submanifold ofℂ6 is a set theoretic complete intersection if sc 1 2 (Y)=0 for some integer s>0.