Noncommutative Maxwell-Chern-Simons theory in 3 dimensions is defined in terms of star product and noncommutative fields. The Seiberg-Witten map is employed to write it in terms of ordinary fields. A parent action is introduced and the dual action is derived. For spatial noncommutativity it is studied up to second order in the noncommutativity parameter theta. A new noncommutative Chern-Simons action is defined in terms of ordinary fields, inspired by the dual action. Moreover, a transformation between noncommuting and ordinary fields is proposed. (C) 2003 Published by Elsevier Science B.V.