Infantile colic is a benign process in which an infant has paroxysms of inconsolable crying for more than three hours per day, more than three days per week, for longer than three weeks. It affects approximately 10% to 40% of infants worldwide and peaks at around six weeks of age, with symptoms resolving by three to six months of age. The incidence is equal between sexes, and there is no correlation with type of feeding (breast vs. bottle), gestational age, or socioeconomic status. The cause of infantile colic is not known; proposed causes include alterations in fecal microflora, intolerance to cow's milk protein or lactose, gastrointestinal immaturity or inflammation, increased serotonin secretion, poor feeding technique, and maternal smoking or nicotine replacement therapy. Colic is a diagnosis of exclusion after a detailed history and physical examination have ruled out concerning causes. Parental support and reassurance are key components of the management of colic. Simethicone and proton pump inhibitors are ineffective for the treatment of colic, and dicyclomine is contraindicated. Treatment options for breastfed infants include the probiotic Lactobacillus reuteri (strain DSM 17938) and reducing maternal dietary allergen intake. Switching to a hydrolyzed formula is an option for formula-fed infants. Evidence does not support chiropractic or osteopathic manipulation, infant massage, swaddling, acupuncture, or herbal supplements.