The potential of paint coated calcium carbide (PCC) as a potent source of soil-applied ethylene was examined in improving different morpho-phenological, physiological and yield attributes in cucumber (Cucumis sativus L.). Ethylene emission was monitored in soil under controlled conditions by the application of 100, 200, 300 and 400 mg pot-1 of PCC over 56 days of incubation which stimulated ethylene production in soil by 8-, 15-, 23- and 31-times, respectively over an unamended control soil. A pot experiment was conducted to evaluate the influence of various rates of PCC on growth and yield of Desi (local) and Bolan-F1 (hybrid) cultivar of cucumber. Application of lower to medium rates (100 to 300 mg pot-1) of PCC strongly increased plant growth, femaleness, photosynthesis and fruit yield compared to control while higher (400 mg pot-1) rate showed inhibitory response on growth and yield components of  both cultivars. PCC rate of 300 mg pot-1 was found most effective in both cultivars in increasing female flower count, photosynthesis, fruit setting, and number of fruits, early fruit yield and total yield. Similarly, plant height and days to female flowering and fruit maturity was decreased at this rate in both cultivars. In both cultivars endogenous ethylene production increased linearly and reached maximum by the application of 400 mg pot-1 PCC but maximum effects regarding early and total fruit yield of cucumber were observed at 300 mg pot-1 PCC. However, plant femaleness, photosynthetic rate and fruit yield in Desi cultivar was more responsive to modulated plant ethylene level than Bolan-F1 cultivar. These data strongly suggested that the positive impact of PCC in low to medium concentrations at plant (transplanting stage), improved morpho-phenological, physiological and yield attributes by increasing the plant ethylene level.