The effect of exogenous methyl jasmonate (MJ) on cucumber plants (Cucumis sativus L.) exposed for 3 days to 4 °C was studied. It was shown that a temperature of 4 °C has a damaging effect on seedlings, causing a significant increase in electrolyte leakage and irreversible inhibition of growth processes. Along with this, an increase in lipid peroxidation was observed in the leaves of the seedlings, as indicated by the accumulation of malondialdehyde (MDA). MJ treatment (1 µM) of plants one day before the onset of cold exposure had a protective effect evidenced, in particular, by a decrease in the MDA level in the leaves. In addition, the leakage of electrolytes from leaf tissues in this case was significantly lower throughout the entire period of exposure to cold, and leaf sizes in seedlings treated with MJ exceeded those in the variant with exposure to cold without MJ pretreatment. It is concluded that MJ can reduce the detrimental effect of low damaging temperature on plants, and the possible mechanisms of this protective effect are briefly discussed.