In this study, we conducted a qualitative and quantitative analysis of anthocyanins, proanthocyanidins, flavonols and triterpenoids in samples of introduced and bred large cranberry fruits from the collection of the National Botanic Garden of Latvia. The highest total anthocyanin levels (8638–9316 µg/g) were detected in the fruit samples of the cranberry cultivars ‘Black Veil’, ‘Franclin’ and ‘Early Black’. The highest total proanthocyanidin levels (2775–3389 µg/g) were found in cranberries of cultivars ‘Kalnciema Agrā’, ‘Kalnciema Tumšā’, ‘Searles’, ‘Howes’, and ‘Kalnciema Ražīgā’. The highest levels of flavonol compounds (1373–1402 µg/g) were detected in cranberries of cultivars ‘Howes’, ‘Black Veil’ and ‘Salaspils Melnās’. The highest levels of triterpenoids (5292–5792 µg/g) were determined in cranberries of cultivars ‘Kalnciema Agrā’, ‘Septembra’, ‘Džbrūklene’ and ‘Early Black’. The results of our study allow for the estimation of differences in the content of secondary metabolites in the fruit samples of the studied cranberry cultivars and for the selection of promising cultivars for further introduction and cultivation in the climatic conditions of the Baltic countries. These results are also important for the selection of the most promising cranberry cultivars for the preparation of cranberry raw material, and the high-quality composition of plant material ensures the effectiveness of cranberry supplements and other cranberry preparations.