Conversion electron Mossbauer spectroscopy (CEMS) was applied to study Fe ultrathin films and Fe/Cr, Cr/Fe interfaces. Based on alloy model in which the Cr atom in the first and second Fe coordination shell decreases the Fe hyperfine field, we are able to show that the Cr/Fe ("lower") interface is smoother than the Fe/Cr ("upper") one. The Fe atoms are distributed over 1 and 2 atomic layers in the lower and upper interfaces, respectively. The CEMS studies were correlated with the magneto-optic Kerr effect measurements of an indirect exchange coupling in Fe/Cr multilayers. In the Fe/Cr/Fe trilayers the antiferromagnetic and non-collinear coupling was observed for the 8 ML and 20 ML Cr spacer thickness, respectively.