Abstract : Impact of the experimentation of irrigation and fertigation on yield of parthenocarpic cucumber under naturally ventilated polyhouse was carried out for two seasons during 2019-20 and 2020-21 at Hi-tech Horticulture unit, Agriculture Research Station, University of Agricultural Sciences, Dharwad. The experiment was conducted to study the effect of different irrigation regimes (I) at I1-(60 % ETc), I2-(80 % ETc), I3-(100 % ETc) and fertigation levels (F) - F1-(60 % RDF), F2-(80 % RDF), F3-(100 % RDF), F4-(120 % RDF) and their interaction on cucumber hybrid under naturally ventilated polyhouse. The studies indicated that there is a significant influence of irrigation and fertigation on growth and yield of parthenocarpic cucumber under polyhouse condition. Among the treatment combinations I2F4 (80 % ETc and 120 % RDF) has recorded highest plant height at 90 days after planting, least days taken for first harvest (35.53 days)with more number days for final harvest (111.65 days), highest fruit length (15.65 cm), higher average fruit weight (158.13 gm), higher number of fruits per vine (24.76), higher yield (18.40 kg m-2) (92.01 q 500m-2) and (184.02 t ha-1). The significant increase in yield was due to better utilization water at 80 per cent ETc and 120 per cent recommended dose of fertilizers by reducing the percolation losses of water and reduction in leaching of nutrients where as compared to other treatment combinations