Powdery mildew, Alternaria 1eaf spot, root rot and phyllody are the major diseases affecting the cultivation of sesame. Twenty entries under Initial Varietal Trial (IVT) and seven entries under Advanced Varietal Trial (AVT) were screened against important diseases of sesame under field (sick plot) conditions. In IVT entries, the diseasesseverityofroot rot ranged between 21.13% (IVT-20-14) to 62.03% (IVT-20-13) and the susceptible check VRI-1 recorded the disease severity of 66.13%. Incidence of phyllody ranged between 13.0% to 20.9%. The check variety VRI-1 recorded 24.3% disease incidence. Powdery mildew incidence ranged between 0 to 2 grade andAlternaria leaf spot incidence ranged from 1 to 3 grade. Among the seven AVT entries screened under sick plot conditions, root rot incidence ranged between 12.1% (AVT-20-4) to 35.2% (AVT-20-7). The susceptible checkvarietyVRI-1 recorded 67.0 % root rot incidence. Phyllody disease incidence in these entries ranged between 9.7% to 15.8% whereas the susceptible check variety VRI-1 recorded 22.4% incidence.