Yes. Tylenol is a brand of acetaminophen (aka paracetamol in rest of world) which is a pain reliever & used to lower fever (anti-pyretic). Aleve is a brand of naproxen, an NSAID (non-steroidal anti-inflammatory drug), which is also a pain reliever & anti-pyretic. So you can take these two together. However, don't take Aleve w/Ibuprofen (aka Motrin, Nuprin, (ibuprofen) Advil) which is also an NSAID.