A 4-month-old baby who can’t roll over is not necessarily pathological, but may be caused by parents not training the child and by the baby growing too fast, being too heavy or too tall. If the child holds his head steadily, can lift his head upright when held vertically or can support his chest when in prone position, and can hold toys in his hands, he can continue to be observed. What parents need to do is to help the baby turn over on his or her side often and let the baby turn over consciously. If the baby can’t lift his head steadily or can’t lift his head in prone position, and has no sense of turning over and lying flat, he needs to go to the growth and development department for developmental assessment.