The present study elucidated the role of triacontanol in regulating seed germination and seedling vigour of four cucumber cultivars under salt stress (50 mM NaCl). Seeds were soaked in aerated solution of triacontanol @ 25 μM, 50 μM for 12 h prior to sowing and untreated seeds were used as control. Priming enhanced the emergence rate, uniformity and early growth of cucumber seedlings under normal and saline conditions. Though, plants exposed to salt stress and seeds not treated with triacontanol showed poor performance in growth, physiology and biochemical attributes. However, priming with 25 and 50 μM triacontanol was very effective in decreasing time to start emergence, improved final emergence, shoot/root lengths, seedling dry weight, gas exchange attributes, chlorophyll and proline contents under saline conditions. Nonetheless, maximum relief from salt stress in all attributes was observed at 50 μM triacontanol. In conclusion, triacontanol can be successfully employed to improve the germination capacity and stand establishment of cucumber under saline conditions by reducing the deleterious effects of salinity.