Today, there are many more adults living with congenital heart disease (CHD) than there are children with CHD. This is because 97% of babies born with CHD survive to adulthood, and 70% of those alive at 18 years live up to 70 years of age. This chapter illustrates some common scenarios encountered during reviews for adult CHD, especially with regard to life-long surveillance post-corrective surgery or palliative surgery. Echocardiography is the mainstay for follow-up assessments in understanding long-term anatomical and physiological derangements of their heart condition.