The overall aim of this study is to analyse and describe reading ability from the second to sixth year of schooling in Sweden (ages 8–13). An intro­ductory study presents the pupils’ reading profiles and also the extent to which teaching in reading comprehension is given at their schools. In a second study, the results and effects of the national test in Swedish in grade three (age 9) are studied and compared with other recognised test data on the development of children’s reading. A total of 428 pupils at four schools participated in the study. Each child was tested once a year during two consecutive school years. In addition to collecting results on the national test for all the pupils in their third year, standardised tests of word decoding ability and reading comprehension were administered to all students in the study. A questionnaire dealing with teaching reading and skills development was answered by 23 teachers. The study reveals that there are stronger links between phonological tasks and reading comprehension for pupils in their first three years than for those in years 4–6. The study also shows that the national test identifies some pupils with reading difficulties but not all of them. A number of pupils who have problems with word decoding nevertheless attain the national test threshold for reading comprehension tasks in the third year. There are also pupils who cannot manage the age-adapted reading comprehension tasks but who still pass the national test in their third year. The findings reveal that teachers work with reading comprehension exercises to only a small extent in both the first three years and second three years of schooling. The study indicates the importance of using a diagnostic approach, so that early and effective measures can be adopted to prevent the emergence of reading comprehension problems.