The article analyses the peculiarities of punctuation of syntactic units – attributes and extended adverbial modifiers – in the simple sentence of the Lithuanian texts of the mid-19th century. To determine the tendencies of punctuation of these parts of the sentence in the written language of the period in question, the original and translated works of prose by Mikalojus Akelaitis, Juozas Silvestras Dovydaitis, Motiejus Valančius, Henrikas Balevičius and Kazimieras Michnevičius-Mikėnas were selected for the study. The study revealed that the punctuation of extended attributes, which go after the modified word, is not settled: they are separated, not separated or separated by commas on one side only. The punctuation of the extended attributes in agreement, which go before the modified word, is strictly defined in the material under analysis – they are not separated by commas. The punctuation of two or several non-extended and/or extended postpositive attributes in agreement is not consistent: they are either not separated at all or separated by a comma on one side (or by a colon in Valančius’ text). Attributes before the modified word expressing the properties of different kinds are separated by commas in order to underline the equal importance of those properties or they are not separated and considered homogeneous. The punctuation of appositions in the given texts is not random and has a rather regular pattern: postpositive extended appositions are usually separated (by commas only); it is not common at all to separate postpositive non-extended appositions. The punctuation of extended adverbial modifiers varies considerably: some prefer to punctuate them (texts by Balevičius, Michnevičius-Mikėnas), yet others tend to avoid punctuation (texts by Valančius, J. S. Dovydaitis and Akelaitis). It is a rather wide-spread phenomenon to use a comma at the end of the extended adverbial modiefier.