The influence on yield and crop value of Burley tobacco (cv B8) of rate and timing of mineral N fertilisation were studied in an experimental layout comprising the combinations of three N rates (100-200-300 kg/ha) by three schedules (NTAT, totally at transplanting; NT40D, totally at 40 days after transplanting; NSPL, 1/3 at transplanting and 2/3 at 40 days after transplanting) by two levels of base organic fertilisation (yes-no). A zero rate N level (N0) was also added as control. The organic fertilisation treatment was applied at soil preparation by broadcasting 500 kg/ha of a commercial fertiliser containing about 14% N, 8% P, 6% K, and 7% organic carbon. Observations were made on cured tobacco yield, leaf value index and some physical leaf properties. Cured leaf yield and crop value increased with organic fertilisation, but the response to mineral N appeared to be dependent both on the organic fertilisation and the N application schedule: without organic the highest yielding schedule was NSPL; with organic the highest yield was obtained with NT40D at the rate of 200 kg/ha, followed by both NTAT and NSPL at the rate of 300 kg/ha. In all cases, though, the N0 control gave yields comparable with those achieved with mineral N applications. Leaf value index was adversely affected by organic fertilisation and by NT40D and NSPL, while increasing linearly with NTAT. Filling value decreased with organic fertilisation at all leaf positions except the lowest and with NTAT and NT40D in absence of organic. Burning rate was affected by the N treatments mainly in the basal leaves, where it increased from NT40D to NSPL to NTAT without organic and in the reverse order with organic.