Lettuce is a valuable leaf vegetable for a well-balanced diet, since it is rich in nutrient elements, has low calories and provides dietary antioxidants. Compared to soil-based cultivation, the hydroponic system is an alternative associated with a shortening of growing cycles and a reduction of wasted water amount. The aim of this study was to analyze the growth of lettuce plants under hydroponic and soil cultivation systems, during three phenological growth stages (45; 47 and 49) according to BBCH scale. During the study different morphological and physiological parameters were evaluated: Plant height (PH); Stem diameter (SD); Fresh mass (FM); Dry mass (DM); Leaf area (LA); Chlorophyll content (CC); Transpiration rate (TR). The research was carried out using a complete randomized design with a 2 × 3 factorial arrangement of cultivation system and growth stages. Plants grown in hydroponic system presented higher values of most parameters, except for DM and TR. The cultivation system had the highest effect on PH, SD and LA. The highest variation between growth stages were observed for PH, LA and CC. Finally, we can conclude that lettuce plants cultivated under hydroponic system, presented better growth parameters associated with higher head weight and yield.