In general, preterm infants should be immunized according to the actual age of the month, without the need to correct the age of the month; the order of immunization is the same as that for full-term infants. In general, if the vital signs of preterm infants are stable after birth and their body weight is more than 2 kg, they can be immunized normally, and there is no difference with full-term infants. However, it should be noted that the BCG vaccine can only be given to preterm infants with a birth weight of <2.5 kg if they weigh ≥2.5 kg and have good growth and development. Critically ill preterm infants should receive the first dose of hepatitis B vaccine as soon as possible after their vital signs stabilize. Thereafter, other vaccinations should be given in a regular program according to the time of the first vaccination. Routine vaccination of preterm infants does not increase the incidence of adverse events compared to term infants. There are no special aspects of post-vaccination care for well-developed preterm infants. It is recommended to consult with a healthcare professional before vaccinating a preterm infant.