An experiment was conducted to assess the effect of sowing date on two cotton varieties MNH552 and MNH554 grown on Ist April, 15th April, Ist. May, 15th May, Ist. June, 15th June, Ist. July and 15th July during 1998 and 1999 under Multan conditions. 15th May and Ist June sown cotton displayed significantly maximum seed cotton yield of 2998 and 2883 kg ha-1 in 1998 and 4027 and 3894 kg ha-1 respectively in 1999 as compared to 595 and 253 kg ha-1 (1998) and 1269 and 223 kg ha-1 (1999) from crop sown on Ist and 15th July respectively. The increase in both sowing dates in seed cotton yield was associated with boll weight and bolls per plant. On average of two years data 15th May produced highest seed cotton yield of 3513 kg ha-1, whereas the lowest figure was 238 kg ha-1 (15th July). Comparing varietal performance MNH552 (2310 kg ha-1) yielded higher as compared to MNH554 (2288 kg ha-1). However two cultivars declined the yield in late planting.