The introduction of water and the absence of flow during hydrostatic testing or layup of pipelines can lead to internal corrosion, making corrosion control a critical concern. Various corrosion mechanisms may be active, including microbiologically influenced corrosion (MIC), under deposit corrosion (UDC), and oxygen corrosion, depending on the service and operating conditions of the pipeline. Chemical treatment is typically used to control corrosion during hydrotesting or layup, but it must be targeted at the applicable corrosion mechanisms and remain effective over the duration of hydrostatic test or layup period. Additionally, the applied chemical treatment must reach metal surfaces susceptible to corrosion. This paper highlights the approach for selection of appropriate mitigation strategy for internal corrosion prevention as part of hydrostatic testing and wet layup. This paper also presents two case studies that illustrate the processes used to identify likely corrosion mechanisms and perform laboratory studies to examine the effects of various chemical mitigation solutions for hydrostatic testing and wet layup.