New data on Lambda production in Au+Au collisions at 11.5 A GeV/c are presented. The measurements cover the rapidity range from y=2.0 to 3.5 and transverse momenta from pt=0.15 GeV/c to 1.5 GeV/c. The rapidity distributions, transverse momentum spectra, and azimuthal distributions are presented for different centralities of the collision. A strong positive directed flow at forward rapidity is observed for semicentral collisions. The measured spectra, yields and directed flow are compared with the predictions of RQMD v2.3 model.