This work was accomplished in Marília county, State of São Paulo - Brazil, with the objective of studying the growth, production, N uptake and correlations between these characteristics, on tissue culture garlic cultivated under high nitrogen levels. Five levels of N were used: 0, 80, 140, 200 and 250 kg/ha in a randomised block design with four replications. The number of leaves per plant and the bulbing ratio increased under high N levels in the soil. The plant height and dry matter accumulation showed a quadratic response, reaching maximum values at N levels of 180 and 164 kg/ha, respectively. The N-accumulation on leaves and bulbs also followed the quadratic behaviour, although only the bulb showed a maximum value of N-accumulation under the level of 182 kg/ha. For total yield, a quadratic effect was observed, increasing up to 234 kg/ha of N. The commercial yield was negatively affected by the high N levels, showing a quadratic effect. The maximum estimated commercial yield (18.74 t/ha) was obtained under 194.4 kg/ha of N. Garlic plants originated from tissue culture had better response to higher N levels than those whose bulbs were multiplied in the field. Highly significant correlations were observed between N-accumulation and the plant production components.