The longitudinal relationship between serum levels of lipoproteins and lifestyle measures (e.g., intake of cholesterol, carbohydrates, saturated fatty acids [SFA], polyunsaturated fatty acids [PUFA], the PUFA/SFA (P:S) ratio, alcohol consumption, smoking behavior, and daily physical activity) was investigated over a period of 15 years in a cohort study (the Amsterdam Growth and Health Study). Members of the cohort were 13 years of age at commencement of the study and were 27 years old at termination. The unique feature of the study presented is that the longitudinal relations were analyzed with generalized estimating equations, a statistical technique in which the relations at different time-points are tested simultaneously. The development of the total serum cholesterol (TC) level was positively related to the intake of cholesterol and negatively to the P:S ratio. The development of high-density-lipoprotein cholesterol (HDL) level was positively related to alcohol consumption and daily physical activity and negatively to smoking behavior. The development of the TC:HDL ratio was negatively related to alcohol consumption and positively to both smoking behavior and carbohydrate intake.