Optimum crop yield is not possible without the timely application and right amount of irrigation water. Since rainfall during rabi is inadequate and uncertain, scheduling of irrigation during critical stages could boost the growth, yield and water productivity of mustard. So, in order to identify critical stages of irrigation for mustard in Northern Telangana Zone, a field experiment was conducted during rabi, 2021-22 at Agricultural college, Jagtial to investigate the effect of irrigation scheduling at different phenological phases on growth and yield of mustard. The experiment was laid out in randomized complete block design with twelve treatments and replicated thrice. Treatments includes two irrigations each at vegetative and flowering stage (T1), two irrigations each at vegetative and siliqua development (T2), two irrigations each at flowering and siliqua development (T3), three irrigations each at vegetative, flowering and siliqua development (T4), three irrigations each at vegetative, pre-flowering and siliqua development (T5), three irrigations each at pre-flowering, siliqua initiation and siliqua development (T6), four irrigations each at vegetative, pre-flowering, flowering and siliqua development (T7), four irrigations each at vegetative, pre-flowering, flowering and siliqua initiation (T8), four irrigations each at vegetative, pre-flowering, siliqua initiation and siliqua development (T9), four irrigations each at pre-flowering, flowering, siliqua initiation and siliqua development (T10), five irrigations each at vegetative, pre-flowering, flowering, siliqua initiation and siliqua development (T11) and scheduling of irrigation at IW/CPE ratio of 1.0 (T12). The results of the experiment revealed that maximum plant height (146 cm), LAI (0.89), dry matter accumulation (416 g m-2), number of siliquae plant -1 (124), number of filled seeds siliquae-1 (13.65), seed yield (1113 kg ha-1) and stover yield (2224 kg ha-1) were recorded with five irrigations each at vegetative, pre-flowering, flowering, siliqua initiation and siliqua development (T11). However, it was on par with irrigation scheduled at IW/CPE ratio of 1.0 (T12). While, the lowest plant height (102 cm), LAI (0.42), dry matter accumulation (198 g m-2), number of siliquae plant -1 (63), number of filled seeds siliquae-1 (10.43), seed yield (431 kg ha-1) and stover yield (923 kg ha-1) was recorded with scheduling two irrigations at vegetative and siliqua development (T2).