At what age is sleep training most successful?

Sleep training works most effectively when both parents and child are ready. Not even the sleep experts can agree on the best time to start-some suggest as early as four months while others suggest that the child will decide when they are ready to sleep. I would not recommend starting any sleep training without speaking to your doctor first, and I find it easiest between five to seven months of age. I don't ever feel it is too late, because for it to be successful, parents must be confident that what they are doing is right for their child and family.