Endotracheal suctioning (ES) is a painful procedure frequently performed in the neonatal intensive care unit. This procedure negatively affects the comfort level of premature neonates. To determine the effect of 2 nonpharmacologic methods, swaddling and the administration of oropharyngeal colostrum, on the pain and comfort levels of preterm neonates during ES. This randomized controlled experimental study comprised 48 intubated premature neonates (swaddling group n =16; oropharyngeal colostrum group n =16; and control group n =16) at 26 to 37weeks of gestation. The neonates were swaddled with a white soft cotton cloth or administered 0.4 mL of oropharyngeal colostrum 2minutes before ES, according to the group in which they were included. Two observers evaluated the pain levels (Premature Infant Pain Profile-Revize [PIPP-R]) and comfort (Newborn Comfort Behavior Scale [COMFORTneo]) of the infants by observing video recordings of before, during, and after the procedure. A significantly lower mean PIPP-R score was found in the swaddling group during ES compared with the control group ( P =.002). The mean COMFORTneo scores of the swaddling and oropharyngeal colostrum groups during ES ( P <.01, P =.002) and the mean PIPP-R and COMFORTneo scores immediately after ES and 5, 10, and 15minutes later were significantly lower than the control group ( P <.005). Swaddling was effective both during and after the procedure, while oropharyngeal colostrum was effective only after the procedure in reducing ES-related pain in premature neonates. Swaddling and oropharyngeal colostrum were effective in increasing comfort both during and after the procedure.