This article is to present etymological analysis of Shtokavian vocabulary related to rain calling rituals in times of summer droughts. The following lexemes were analyzed: 'dodola', as a basic word and also prporuse', carójice', as dialect alternatives with the same meaning: 1. a) pl. - rain calling ritual, b) the main character during the ritual; 2. the time from the beginning of May till mid-August when a ritual took place. All these lexemes were written down for the first time at the beginning of the 19th century by Vuk Stefanovic Karadzic. Nevertheless the etymological analysis proves that the lexemes belong to the oldest parts of vocabulary. The form 'dodola' is derived from a folksong refrain sang during the ritual: 'oj dodo le'. The refrain itself is not that clear and perhaps it's a form of tabuisation of the word 'bog' which frequently consisted in phonetic change. Researches in domain of religious studies indicate an onomatopoeic origin of the word and associate it with the name of female partner of the pagan deity. Etymological analysis of the form 'prporuse' points to similar conclusion and comparing vocabulary items let us to regard it as slavism in Balkan languages. The study of Slavic mythology allow reconstruction of the Slav ancestral '*Perperuna' that seems to be a female form from the name of 'Perun' created by a root reduplication and this morphological process was often in ritual spells. Lexeme 'carnjice' has two explanations. This may be derived either from Italian ciarliero 'the mane, who dotes'or from 'car', a Slavic magical term. A portmanteau of both words mentioned above can be another explanation.