The paper is concerned with influences of structural lattice defects mainly in metals on Mössbauer studies and contrary-wise with the information about these defects available from Mössbauer studies. First a short review of present knowledge about the production of defects in collision processes of highly energetic particles (« external » and « internal » implantation) and in nuclear reactions is given. Defect migration leading to defect reactions and annealing in on-line experiments and in experiments involving long radioactive half-life is reviewed as well. After a comparison of different methods of studying structural lattice defects, the particular information uniquely available from microscopic methods as the Mössbauer effect and related methods is discussed. In the second part of the paper the mutual influence of defects and Mössbauer studies is demonstrated in a survey of defect relevant Mössbauer experiments. The examples can be divided into two groups : 1. « Correlated damage » ; 2. « Uncorrelated damage » followed by trapping of the defects at Mössbauer impurities. Comments concerning the results of various experiments are presented. Finally a recent experiment is discussed in greater length. In this experiment Co57(Fe57) impurities in aluminum trap interstitials produced by low-temperature irradiation in aluminum during the interstitials' migration, thus permitting the microscopic investigation of the interstitials with the Co57(Fe57) atoms as microprobes.