This contribution looks at the relation between spatial planning law and soil remediation law when a contaminated site is being developed. The relation between both legal fields clearly emerges when the land use of the site must be modified in function of the future land use in view. This will have an impact on the remediation criterion as well as on the remediation objective. Another point of contact is the link between a soil remediation and a town planning permit. A good harmony between the spatial planning law and the soil remediation law is essential for the development of a contaminated site. After a brief European perspective, the contribution mainly focuses as a case study on the situation in the Flemish Region (Belgium).