Micro- and macro-archaeobotanical investigations were carried out on a selection of Late Avar graves from the archaeological site of Nuštar with the aim to reveal interactions between burial customs and plants of the Late Avar (710–810) population in Eastern Croatia (Croatian Danube region). During the excavation 108 soil and sediment samples were collected from the graves; due to the fact that there was a great amount of material, samples were collected from different depths and places in graves. Moreover, a little less than 100 whole vessel contents were recovered. Twenty sediment samples from grave-fill for macro-archaeobotanical study, as well as ten samples from vessels for micro-archaeobotanical study were chosen according to a “difference key” (samples from all gender and age and different burials). Overall the archaeobotanical assemblages were poor with none of the samples yielding high amounts of seed or fruit remains. Thus, only six different cereals and three different weed species were identified. Cereals form 67.31% of the entire assemblage, whilst weeds form 12.50% and food remains 15.38%. Phytolith analyses also show the presence of cereal related phytoliths, but most of the samples were considered sterile. Based on the micro- and macro-archaeobotanical investigations of selected graves from the Late Avar cemetery we may consider that the use of plants in burial customs at Nuštar did not play a significant role. In light of previous studies at Late Avar settlements and cemeteries in the surrounding geographical environment (Carpathian Basin, and Middle Danube valley) animal-derived products might have therefore had a more prominent role in ritual and burial contexts.