In shrinking cities, mainly defined by a loss of population, infrastructures such as networks, housing, or schools are affected: due to the decline of the population, infrastructures appear underused. This raises unusual concerns for the municipalities mainly because infrastructures are planned for a long-term purpose and to supply high demand. The adaptation of infrastructures is needed; however, this is complex to implement for the concerned municipalities due to the lack of financial resources or uncertainties on the evolution of the demand. This poster presented at the conference CITTA (university of Porto) aimed at introducing on the concept of infrastructure, the challenge for planning infrastructure in shrinking cities and the need to further analysed adaptation strategies in a shrinkage context.