Plotless sampling techniques, linear recordings of distances among random trees or points and trees were developed to overcome some limitations of plot-based or quadrat methods by reducing time consuming, sampling effort, etc. However, research works proved that some points need to be clarified in order to provide a more useful guidelines for ecologists. The main objective of this study is to make a critical review of literature on plotless sampling techniques in vegetation studies. For this purpose, most original studies published and focused on plotless techniques in plant communities were identified via Keywords searching on scientific database websites and additional references from retrieved articles. Thereafter, about hundred papers were sampled in this review through careful reading of the abstract, methods and results. This study revealed that plotless sampling methods are mainly used to estimate population density. Furthermore, this study showed that among the plotless sampling methods that were described, some remains slightly documented in ecology to date. Results obtained also showed that the spatial distribution of organisms impacted the performance of these methods. All plotless sampling methods recorded their best performance when the population is randomly distributed. When the population is uniformly or contagiously (clump) distributed, most of them produced the largest bias of density estimate. However, over all spatial patterns, distance measurements at least to the third nearest neighbour were the best preferred methods. Therefore, further research works need to control this bias, to continue some investigations on those methods mainly on measurement errors and detection process.