Tobacco (Nicotiana tobaccum L.) is one of the most important cash crops in Indian Agriculture. Currently India accounts for Ĕ 10 percent of world's area and Ĕ9 percent of tobacco production and is the second largest producer in the world. Tamil Nadu is known for quality cigar production and is raised on an area of about 250 hectares in the districts of Dindigul, Trichy and Salem. A number of varieties are used in the manufacture of cigar in Tamil Nadu and the popular among them are Vellaivazhai and Karuvazhai. The major nutrients essentials for growth and development of tobacco plant are nitrogen, phosphorus, potassium, calcium, magnesium and sulphur. A field experiment was conducted at farmers field at Thoppampatti village, Palani Taluk of Dindigul District, Tamil Nadu during December 2001 to May 2002 to study the response of phosphorus, potassium and magnesium on yield and quality of cigar tobacco variety Karuvazhai (KV 1). The soil of the experiment site was sandy loam belonging to Irugur series. The experiment involved fourteen treatments, namely, two levels of P, viz., 125 and 150 kg P2O5 ha-1, three levels of K, viz., 150, 200 and 250 kg K2O ha-1 and two level of Mg, viz., 50 and 100 kg Mg ha-1 with a common dose of N (60kg ha-1) and S (150 kg ha-1), besides the state recommended levels of N, P and K and also an absolute control without any fertilizer application. The treatments were replicated four times in a randomized block design. The results revealed that the cured leaf and whole plant yields increased with the increased application of N, P, K and Mg fertilizers (N60 : P125 : K250 : Mg100 ) with 43.2 per cent increase in yield over the state recommended level (N40 : P100 : K100 : Mg0). Omission of either P or K or Mg or S resulted in 7.7, 10.6, 10.9 and 9.0 per cent decline in yield respectively over addition of P, K, Mg and S fertilizers (N60 : P125 : K150 : Mg50). Quality of cigar tobacco, viz., nicotine (0.60 to 1.18 and 0.78 to 1.47 respectively for stem and leaf) and leaf burn (22 to 34 seconds of leaf combustibility) were improved by enhanced level of K and Mg where as the chloride content was maintained below the critical limit (2%) even up to 250 kg K2O ha-1. Application of K and Mg through MOP and MgCl2 increased the chloride content to a toxic level (> 2%) than the other sources of fertilizers.