Late Neolithic I covers the period 5300-4800 BC. It includes the so-called Pre-Dimini phases and is characterized by a great variety of pottery styles. In Thessaly these styles have been classified by archaeologists as the phases Tsangli-Larisa and Arapi, recorded though in other geographical regions of Greece as well.

From the initial phase of the Late Neolithic I (Tsangli-Larisa) a considerable increase in the number of settlements in the plains has been observed, which lead to a population boom and an intensification in cultivation. The architectural structure of the settlements differed from that of previous periods. Settlements consisted of large buildings, rectangular and megaron-type (Visviki), timber-post framed (Sitagroi, Dikili Tash-Macedonia) or with stone foundations. Food-preparation constructions (hearths, ovens) were normally found in the interior of the houses. Many settlements were surrounded by ditches 4-6 metres wide and 1,5 to 3,5 metres deep (e.g. Otzaki, Galini, Makriyialos). These ditches are believed to have been used either to protect the inhabitants from wild animals or to demarcate the limits of the settlement and thus protect goods. The lakeside settlement of Dispilio-Kastoria, the first lakeside settlement to be excavated in Greece and one of the most important in Europe, had a distinctive structure: the houses were built inside the lake, upon timber-post framed platforms.
The number of community members amounted to 100-300 individuals. A nuclear family strucuture formed the social unit of the Neolithic community during this period and up to the Final Neolithic. Burial customs consisted of burials of the dead in simple pits, and organized cemeteries with individual or group cremations (Platia Magoula Zarkou, Soufli Magoula-Thessaly).

The farming economy intensified and grew with the clearance of woody and shrubby areas in order to secure arable lands and grazing fields. Farming was based on the cultivation of cereals (einkorn and emmer wheat, barley) which were known from the Pre-Pottery Neolithic, while from this period onwards bread wheat, millet, rye and oat were cultivated. To the already familiar pulses, lentils, peas, broad beans, Vicia evilia and chickpeas were added. Cattle and pigs acquired a special importance in the diet of Neolithic man, while sheep and goats were raised for their wool which was used in weaving. In Thessaly specialization in the production of grey and black burnished pottery (Tsangli-Larisa phase) took place and was traded to other regions through exchange networks.
The typical pottery styles of the early Late Neolithic were grey, monochrome or decorated (Tsangli) and black burnished pottery (Larisa). The discovery of these two pottery styles in the same archaeological layer in recent excavations in Platia Magoula Zarkou and Makrychori 2, places the Larisa phase at the beginning of the Late Neolithic and not at its end, as was earlier believed. At the beginning of the Late Neolithic, black painted designs on a red background has been encountered in vases, while polychrome and matt painted pottery was widely disseminated in the whole Aegean area. In the next Arapi phase, painted designs in black or white on a red background was characteristic, as well as the appearance of spirals as a design motif for the first time, that was to predominate during Late Neolithic II. Finally, the figurines of this period were schematic.