Pain, when treated inadequately, puts preterm infants at a greater risk of developing clinical and behavioural sequelae because of their immature pain system. Preterm infants in need of intensive care are repeatedly and persistently exposed to noxious stimuli, and this happens during a critical window of their brain development with peak rates of brain growth, exuberant synaptogenesis and the developmental regulation of specific receptor populations. Nearly two-thirds of infants born at less than 29 weeks' gestation require mechanical ventilation for some duration during the newborn period. These neonates are endotracheally intubated and require repeated endotracheal suctioning. Endotracheal suctioning is identified as one of the most frequent and most painful procedures in premature infants, causing moderate to severe pain. Even with improved nursing performance and standard procedures based on neonatal needs, endotracheal suctioning remains associated with mild pain. To evaluate the benefits and harms of non-pharmacological interventions for the prevention of pain during endotracheal suctioning in mechanically ventilated neonates. Non-pharmacological interventions were compared to no intervention, standard care or another non-pharmacological intervention. We conducted searches in June 2023 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, Embase, CINAHL and three trial registries. We searched the reference lists of related systematic reviews, and of studies selected for inclusion. We included randomised controlled trials (RCTs), quasi-RCTs and cluster-RCTs that included term and preterm neonates who were mechanically ventilated via endotracheal tube or via tracheostomy tube and required endotracheal suctioning performed by doctors, nurses, physiotherapists or other healthcare professionals. Our main outcome measures were validated composite pain scores (including a combination of behavioural, physiological and contextual indicators). Secondary outcomes included separate physiological and behavioural pain indicators. We used standard methodological procedures expected by Cochrane. For continuous outcome measures, we used a fixed-effect model and reported mean differences (MDs) with 95% confidence intervals (CIs). For categorical outcomes, we reported the typical risk ratio (RR) and risk difference (RD) and 95% CIs. We assessed risk of bias using the Cochrane RoB 1 tool, and assessed the certainty of the evidence using GRADE. We included eight RCTs (nine reports), which enroled 386 infants, in our review. Five of the eight studies were included in a meta-analysis. All studies enrolled preterm neonates. Facilitated tucking versus standard care (four studies) Facilitated tucking probably reduces Premature Infant Pain Profile (PIPP) score during endotracheal suctioning (MD -2.76, 95% CI 3.57 to 1.96; I² = 82%; 4 studies, 148 infants; moderate-certainty evidence). Facilitated tucking probably has little or no effect during endotracheal suctioning on: heart rate (MD -3.06 beats per minute (bpm), 95% CI -9.33 to 3.21; I² = 0%; 2 studies, 80 infants; low-certainty evidence); oxygen saturation (MD 0.87, 95% CI -1.33 to 3.08; I² = 0%; 2 studies, 80 infants; low-certainty evidence); or stress and defensive behaviours (SDB) (MD -1.20, 95% CI -3.47 to 1.07; 1 study, 20 infants; low-certainty evidence). Facilitated tucking may result in a slight increase in self-regulatory behaviours (SRB) during endotracheal suctioning (MD 0.90, 95% CI 0.20 to 1.60; 1 study, 20 infants; low-certainty evidence). No studies reported intraventricular haemorrhage (IVH). Familiar odour versus standard care (one study) Familiar odour during endotracheal suctioning probably has little or no effect on: PIPP score (MD -0.30, 95% CI -2.15 to 1.55; 1 study, 40 infants; low-certainty evidence); heart rate (MD -6.30 bpm, 95% CI -16.04 to 3.44; 1 study, 40 infants; low-certainty evidence); or oxygen saturation during endotracheal suctioning (MD -0.80, 95% CI -4.82 to 3.22; 1 study, 40 infants; low-certainty evidence). No studies reported SRB, SDB or IVH. White noise (one study) White noise during endotracheal suctioning probably has little or no effect on PIPP (MD -0.65, 95% CI -2.51 to 1.21; 1 study, 40 infants; low-certainty evidence); heart rate (MD -1.85 bpm, 95% CI -11.46 to 7.76; 1 study, 40 infants; low-certainty evidence); or oxygen saturation (MD 2.25, 95% CI -2.03 to 6.53; 1 study, 40 infants; low-certainty evidence). No studies reported SRB, SDB or IVH. Facilitated tucking / four-handed care / gentle human touch probably reduces PIPP score. The evidence of a single study suggests that facilitated tucking / four-handed care / gentle human touch slightly increases self-regulatory and approach behaviours during endotracheal suctioning. Based on a single study, familiar odour and white noise have little or no effect on any of the outcomes compared to no intervention. The use of expressed breast milk or oral sucrose suggests that there is no discernible advantage of one method over the other for reducing pain during endotracheal suctioning. None of the studies reported on any of the prespecified secondary outcomes of adverse events.