Children often develop make-believe companions who share playtime and other activities with them. In most instances, children who have an imaginary friend are quite normal and healthy, and are merely engaging in a form of creative play. While there is a somewhat standard age at which many children lose their imaginary friends, there is no specific age at which a child is too old to have one. Parents should be concerned not with how old the child is, but instead with why the imaginary friend is still necessary in the child's life. A child of any age who has both imaginary and real friends is probably developing good social skills.

Imaginary friends often emerge during the early pre-school years. Why children create these pretend companions is not entirely clear. A common myth is that a child who has an imaginary friend is unfulfilled or bored. It is more likely that imaginary friends are an expression of a child's imagination and creativity. Usually, imaginary friends disappear or "die" as their creator develops better interpersonal awareness, which frequently occurs between the ages of four and seven.

Some parents become concerned when an older child continues to cling to the idea of an imaginary friend. They worry that the child is unable to tell the difference between fantasy and reality, or that the child is developing unhealthy habits associated with his or her imaginary companion. Most of these concerns are unnecessary; the majority of children who have imaginary friends are aware that these friends are not real. Children also do not tend to blame their imaginary friends for bad behavior; more often than not, imaginary companions are role models to the children who invented them.

Problems arise when a child of any age prefers the company of an imaginary friend to spending time with his or her peers. Many children who form imaginary friendships are extroverted and naturally very social, and therefore do not have trouble forming similar bonds with other children in the real world. If a child has no other friends besides the imaginary companion, however, then that child may be using the imaginary friend to combat feelings of loneliness and isolation. Exclusively preferring imaginary companions to real ones may also be an indication of reduced social skills, so children who show these preferences should be encouraged to try new activities and meet new potential playmates.

While an older child who maintains imaginary friendships alongside real life ones is probably emotionally healthy, the stigma of having imaginary friends later in life can still cause problems. Many people assume that because imaginary companionship is usually sought by younger children, having an imaginary friend is a sign of immaturity. Adolescents and teenagers in particular are often preoccupied with appearing adult and mature, so a middle- or high-school aged child who still has an imaginary friend may be subject to ridicule from his or her peers.