Since 1995 all Swedish compulsory schools have been required to establish Individual Educational Plans (IEPs) for pupils with special educational needs. According to the Swedish Education Act such a plan should be drawn up if pupils do not achieve the goals in the curriculum or the syllabus. The process of IEPs covers a prior investigation to identify and assess what kind of problems or difficulties a pupil has. These investigations should be the basis for decision to ensure that the pupils get adequate support for their needs. In the current study we examine the use of IEPs for pupils with reading difficulties. Data in the study comprised 150 IEPs. One important part of the analysis of the IEPs included quality aspects of investigations and interventions. The results show a large variation of the quality for both. In many cases there is a lack of prior investigation in the IEPs and in other cases a limited connection between the assessments of the investigations and the interventions. Furthermore, the results indicate interventions based on assessments of the investigations, generally show a higher quality level. Therefore, the key conclusion is that investigations are crucial in designing interventions and establishing IEPs.