Mini tubers are the starting materials of a disease-free seed potato production scheme. Low multiplication rates as well as non-homogenous tuber size distribution are considered the main constraints of a conventional mini tuber production system. In recent years, an aeroponics production system has been developed to overcome the aforementioned problems. It has previously been observed that this system allows multiple harvests with an average yield of 20–50 mini tubers per plant. Several factors, such as cultivar, planting density, nutrient composition of the mist solution, spraying interval and duration and lighting also affect both tuber number and tuber size. However, less attention has been paid to the association of these factors with the aeroponics system. This paper highlights the importance of planting density effect on conventional and aeroponics system. The mini tuber production performances of three potato cultivars (Hermes, Marabel and Sante) were compared at four different planting densities (25, 50, 100 and 200 plants/m2) under both conventional and aeroponics systems in two production cycles. The number of tubers per plant increased with decreasing planting density, being highest at 25 plants/m2 and lowest at 200 plants/m2 for both cycles. Mean tuber number in the aeroponic system was 19.85 tubers per plant at 25 plants/m2 and 13.20 tubers per plant at 200 plants/m2. As the number of tubers per plant decreased, so did their size. As planting density increased, tuber yield per plant both in aeroponics and conventional system decreased, but in general, tuber yield per plant was higher in aeroponics than in the conventional system. In the 1st cycle, the number of tubers per m2 for Hermes, Sante and Marabel was 290, 364 and 334, respectively, in the conventional system and 787, 1021 and 1168, respectively, in the aeroponics system. Similar numbers were recorded in the 2nd cycle. The average tuber weight was higher in the conventional than in the aeroponics system. Tuber yield/m2 in this study varied from 5.9 to 9.3 kg/m2 in the aeroponics system, about twice as high as in the conventional system.