Previous investigations of 1 repetition maximum bench press (1RM BP) performance have been either descriptive or have explored a limited number of contributing variables. The purpose of this study was to investigate the interplay between structural, technical, and neuromuscular factors in relation to 1RM BP in competitive powerlifters. Thirteen national and international level male powerlifters (26 ± 9 years, 178 ± 6 cm, and 93.8 ± 9.9 kg) visited the laboratory twice. Anthropometric and ultrasound measures were taken on the first visit, whereas performance measures (voluntary activation level, isokinetic strength, and kinetic, kinematic, and electromyographic measurements during 1RM BP) were recorded on the second visit. Correlation and multiple regression were used to investigate the contribution of structural, technical, and neuromuscular variables to 1RM BP corrected for body mass using the Wilks coefficient. The highest degree of association was shown for structural (lean and bone mass, brachial index, arm circumference, and agonist cross-sectional area [CSA]; r = 0.58-0.74) followed by neuromuscular factors (elbow and shoulder flexion strength; r = 0.57-0.71), whereas technical factors did not correlate with 1RM BP performance (r ≤ 0.49). The multiple regression showed that lean body mass, brachial index, and isometric shoulder flexion torque predicted 59% of the common variance in 1RM BP. These data suggest that in a sample of elite competitive powerlifters, multiple factors contribute to 1RM BP with variables such as lean body mass, the agonist CSA, brachial index, and strength of the elbow and shoulder flexors being the greatest predictors of performance.