Borderline intellectual functioning (BIF) is characterized by cognitive impairment and deficits in adaptive functioning. Despite affecting a significant proportion of the population, BIF still remains underdiagnosed and poorly understood. In addition to cognitive impairments across a range of domains, individuals with BIF face a greater risk of academic failure and often require special educational support. They suffer from emotional problems, such as difficulties with emotional awareness, anxiety, depressed mood, and unhappiness. Individuals with BIF are more likely to have an impairment of social and adaptive functioning. Furthermore, individuals with BIF are at higher risk of physical and mental health problems, often receive inadequate treatment, and have a poorer prognosis. This review aims to enhance the understanding of clinicians, educators, and policymakers by providing an overview of the characteristics of BIF and its associated challenges, ultimately contributing to the improvement of support systems for individuals with BIF.