The article is part of a study aimed at a comparative analysis of the peculiarities of Ukrainian pysanky and Lithuanian margučiai in the context of pre-Christian and Christian paradigms of world-view: their role in the ritual culture of Lithuania and Ukraine, the symbolism of decoration, and the technique of performance. The aim of the article is to study the ritual functions of Ukrainian pysanky and Lithuanian margučiai. The research revealed the variability of the names of Ukrainian and Lithuanian ritual eggs in the context of pre-Christian and Christian cultures (the difference between the Ukrainian pysanka, the Lithuanian margutis, and Easter eggs); the similarities and differences in their use in traditional rites of choosing a pair and commemorating ancestors in Lithuania and Ukraine; and their gradual structural and semantic changes under the influence of Christian culture. The foundations are laid for the reconstruction of the original form and content of the rites in which pysanka, krashanka and margutis were (and are) used.