Field experiment was conducted during 2003 and 2004 in the Research Area of Agronomy Department, CCS Haryana Agricultural University, Hisar to study the effect of irrigation frequency on residual behaviour of sulfosulfuron applied in wheat on succeeding sorghum crop grown in rotation. Residual effect of sulfosulfuron was assessed by conducting bioassay studies on sorghum in a split plot design with three irrigation levels (3, 4 and 5) in the main plots and weed control treatments (sulfosulfuron 25 and 50 g/ha, weedy and weed free) in the sub-plots. After harvest of wheat, sorghum crop was planted after slight disking without disturbing the original layout. Sulfosulfuron applied in wheat was found to persist even after 150 days after its application in wheat and its residues in the soil medium caused phytotoxicity to succeeding crop of sorghum. Plant population, plant height, number of leaves per plant, dry shoot and root weight and fodder yield of sorghum were significantly reduced by sulfosulfuron. At 60 DAS, 50 g sulfosulfuron applied in wheat reduced sorghum plant height, dry shoot and root weight per plant by 56, 50, 70 and 57, 51, 71% during the first and second year, respectively, over untreated control. Similarly, fodder yield was reduced by 73 and 75% by 50 g sulfosulfuron compared to untreated control in first and second year of investigation, respectively. The residual effect of sulfosulfuron on sorghum was not found to be mediated by irrigation frequency. Neither the growth parameters nor the fodder yield of sorghum were affected significantly by number of irrigations applied in wheat. Therefore, it can be inferred that increasing irrigation frequencies neither helped in degradation nor in leaching of sulfosulfuron and sorghum should not be planted in rotation with wheat where sulfosulfuron has been applied in wheat.