Performance-predictive parameters have been established for rowers representing different quality levels, sexes, weight categories and classifications, but none have been designed for very young rowers (age <14). The objective of this study was to predict 1000-m rowing ergometer performance based on 12 anthropometric and six physiological variables in 48 male rowers (age range 12.0-13.9 year; mean+/-S.D. 12.94+/-0.61) and to determine the key parameters that would perhaps provide a scientific basis for talent identification and the selection process in rowing. The subjects completed an incremental maximal treadmill test. Their body height (r=-0.79), body mass (r=-0.60), lean body mass (r=-0.82), leg length (r=-0.72), arm length (r=-0.71), bicristal diameter (r=-0.63), biacromial diameter (r=-0.73), upper arm girth (r=-0.34), forearm girth (r=-0.63), thigh girth (r=-0.29), calf girth (r=-0.54), maximal oxygen uptake (in L/min, r=-0.89; and in mL/kg/min, r=-0.36), maximal ventilation (r=-0.77), and oxygen uptake at ventilatory anaerobic threshold (r=-0.87) correlated with 1000-m time (p<0.05), while percent body fat, percent of maximal oxygen uptake at ventilatory anaerobic threshold and maximal lactate did not. Performance correlated significantly with age (r=-0.46; p<0.01), so it was important to consider this effect in the resulting regression models. Multiple regression procedures indicated that the model comprising anthropometric and physiological variables combined best predicts performance (R(2)=0.85), followed by models that comprised physiological (R(2)=0.80) and anthropometric (R(2)=0.76) variables alone. In conclusion, in rowers aged 12-13 year a higher aerobic capacity (as measured by maximal oxygen uptake in L/min), and a larger body size are beneficial for performance over 1000-m rowing ergometer distance.