Abstract <p>The effect of continuous lighting used throughout the entire production cycle or applied as pre-harvest treatment (1–4 days before harvesting) on productivity and nutritional value of rapini microgreens (<i>Brassica rapa</i> L. subsp. <i>sylvestris</i> L. Janch. var. <i>esculenta</i> Hort.) was studied. Plants were grown using different light regimes: 16-h photoperiod; 24-h photoperiod; and 16-h photoperiod followed by 24 h photoperiod during the last 1, 2, 3, or 4 days of the production cycle. The use of continuous lighting throughout the entire production cycle led to a twofold increase in plant yields and also caused an increase in the content of nutrients (16% soluble carbohydrates, 20% proteins) and functional substances (67% anthocyanins, almost three times flavonoids and 9% proline), as well as the activity of antioxidant enzymes, while simultaneously reducing the nitrate content by two times compared to a standard 16-h photoperiod. The obtained results also showed that an increase in the nutritional value and biosafety of rapini microgreens is possible by using of continuous lighting for 2–3 days at the end of the production cycle (immediately before harvesting). In this case, shorter periods of 24-h lighting, on the one hand, significantly reduce energy costs and increase the efficiency of microgreen production and, on the other hand, reduce potential risks associated with possible photodamage to plants.</p>