The subject of air pollution in homes is of interest for people from various backgrounds. Medical doctors, environmentalists, building engineers, public health officers, gas industry and consumer organisations all have to deal with indoor air quality problems in one way or the other. It is therefore necessary to introduce briefly several issues of indoor air pollution, which may be commom knowledge for some readers but not for others.The report is devided in two parts; one which describes the study and one which contains the results. The figures and tables are separated from the text.In part 1, the subject of air pollution in homes and the background of the study are introduced in chapter 1. Chapter 2 gives an overview of indoor air pollution research methodology and sketches the current state of knowledge. In chapter 3, the study design is presented; this chaper is arranged according to the three main measurement programs which form the body of the study. The statistical techniques, which were used for the data analysis in part 2, are briefly introduced in the final part of chapter 3.Part 2 presents the results of the study. First, a description is given of some general characteristics of the homes which were studied. In chapters 3 to 6, the measurement results for the pollutants under study are treated separately. In these chapters, the associations between indoor pollutant levels and characteristics of the homes are described and each chapter ends with a summary and discussion. In the final chapter, a general discussion on air pollution in Dutch homes is given from the perspective of public health.