The experiment on optimization of plant density inside a green house for growing carnation is a very important area for present day production and productivity. The results of the study on optimization of planting density in carnation led to the inference that planting density in treatment T4 (check) (15 x 15 cm with 36 plants/m2) proved better in terms of flower quality parameters namely early flower bud appearance, bud opening, longest duration of flowering, chlorophyll content and more number of flowers per plant due to congenial micro climate between the plants for the plant growth and flowering. Though the percentage of ‘A’ grade quality flowers were higher in treatment T3 (20 x 20 cm with 20 plants/m2), the number of plants and flower yield per sq. m. in this treatment was very less. Hence, treatment T4 (check) with 15 x 15 cm spacing may convincingly be followed for obtaining more number of flowers per plant and per unit area and value in terms of economic success of the crop.