I’d say it depends on the maturity and responsibility level of that teenager. I think preteen age (11 and 12) is way too young to assume the responsibility for another person’s child (or even a younger sibling). A 13-year old may start babysitting in most states to make some extra money, but I think that he or she should only be entrusted with older children between ages 7-9, never very young children. For infants, toddlers, preschoolers and Kindergarteners I would suggest finding a reliable teen who is at least 15 or 16 years old (preferably a little older even) and who has had previous experience dealing effectively and caringly with younger children (either through previous babysitting jobs or by watching and tending to their own younger siblings). It is important when choosing a babysitter to interview this teen and have him/her meet your child prior to their first time spent together. This way you have the opportunity to observe how the teen interacts with your child and how your child responds to the sitter. Be sure to ask the teen sufficient amounts of questions that quench your curiosity and put to rest any fears or uneasiness you may experience. Ask him/her how he would handle a given situation, for example when your child is sad, upset, won’t listen, or acts out. This will help you decide whether this particular sitter is a great caretaker match for your child and whether his/her presence in your home would allow you to feel comfortable enough to go about your business until you return back home.