The paper discusses social impact assessments (SIA) for mining projects in light of the international principles and guidelines for such assessments and the academic literature in the field. The data consist of environmental impact assessment (EIA) programmes and reports for six mining projects that have started up in northern Finland in the 2000s. A first observation is that the role of the SIAs in the EIA programmes and reports studied was quite minor: measured in number of pages, the assessments account for three or four percent of the total. This study analyses the data collection, research methodology and conceptual premises used in the SIAs. It concludes that the assessments do not fully meet the high standards of the international principles and guidelines set out for them: for example, elderly men are over-represented in the data and no efforts were made to identify and bring to the fore vulnerable groups. Moreover, the reliability of the assessments is difficult to gauge, because the qualitative methods are not described and where quantitative methods were used, details such as non-response rates to questionnaires are not discussed. At the end of the paper, the SIAs are discussed in terms of Jürgen Habermas’ theory of knowledge interests, with the conclusion that the assessments continue the empirical analytical tradition of the social sciences and exhibit a technical knowledge interest.