The experiment was conducted at Department of Vegetable Science, College of Horticulture, Mudigere, during the rabi season in the year 2014-15 to study the effect of plant geometry and growth regulators on growth and seed yield of radish (Raphanus sativus L.) Cv. Pusa Chetki. The experiment consists of two spacing levels (45 × 45 cm and 30 × 30 cm) and five levels of growth regulators (GA3 200 ppm, GA3 250 ppm, NAA 200 ppm, NAA 250 ppm and control) in all possible combinations were assessed for growth and seed yield parameters. Regarding the plant spacing, the closer spacing (30 × 30 cm) resulted in maximum Leaf area index (LAI) and Net assimilation rate (NAR), whereas all other growth and morphological parameters like Absolute growth rate (AGR), plant height, number of leaves per plant, number of branches per plant, leaf length, fresh and dry weight of leaves, stem diameter, fresh and dry weight of stem, Chlorophyll content in leaves, induced early flowering and pod weight were found maximum with wider spacing (45 × 45 cm). Decreasing plant density significantly reduces the seed yield per plot (0.36 kg). All the morphological, growth, biochemical and seed yield parameters were found to be maximum with the application of GA3 250 ppm (G2).