The local dialects of the Slivno area were a part of the old Poneretvanski West-Štokavian dialect, and are today a part of East Herzegovinian dialect, its Slivno-Zažablje type. These local dialects were exposed to migrations and were on the very border of old Štakavian and Šćakavian, and contemporary Ijekavian and Ikavian dialects, and were in contact with South Čakavian speeches. In this work, based on field research, the phonological and morphological characteristics of the local dialects of Slivno Ravno, Mihalj, Blace and Podgradina are analyzed. The phonological description includes the presentation of vowel, consonant and prosodic systems, and the morphological one describes the declination of nouns, pronouns, numbers and adjectives, the conjugation of verbs, and the recorded invariable parts of speech. Since the place and the type of accent are essential within the paradigm of variable parts of speech, the morphological part presents an analysis of accent types of nouns and adjectives, which determined the existence of archaic forms (preservation of mobility in a. p. C, accent skipping, preservation of shortness in d./l./i. and preservation of rising tone in L. of nouns of all genders, preservation of original a. p. c in adjectives similar to glȗv−glúva−glȗvo 'deaf') in the local dialects of Slivno Ravno and Mihalj, while the local dialects of Blace, and especially Podgradina have many alternations and innovations. Although the south border of Ijekavian and Ikavian dialects mainly follows the river Neretva, the phonological description has shown that there are deviations in the speeches of Slivno area, which are not unified by yat reflexes. The local dialect of Mihalj stands out because its yat reflex can be bisyllabic, which is a very rare phenomenon in Štokavian dialects in Croatia. The phonological and morphological description clearly determined the characteristics of Slivno type, and differentiated them from Zažablje type. Since the morphological descriptions of Neoštokavian local dialects containing thorough analysis of accent types of nouns and adjectives are extremely rare, we believe that many confirmations and examples will help in clarification of certain accentological dilemmas, while the archaisms will help the reconstruction of Proto-Slavic and Balto-Slavic accent systems, and especially in the presentation of the development of Croatian accentuation. With the research of unstudied dialects of Blace, Mihalj and Podgradina, the dialectological picture of East-Herzegovinian dialect is enriched, a dialect in which the data on the area between Neretva and Dubrovnik is poor and thus comparison to other, especially contact dialects is enabled.