UNLABELLED: We present MASiVE, an expertly built tool for the large-scale, yet sensitive and highly accurate, discovery, preliminary analysis and insertion age estimation of intact Sirevirus LTR-retrotransposons in plant genomic sequences. Validation was based on the recently available and annotated large maize chromosome one. Results show a considerable improvement in the annotation of Sireviruses, and support our approach as an important addition to the bioinformatics toolbox of plant biologists. AVAILABILITY: PERL source code and essential files are available online at http://bat.ina.certh.gr/tools/masive/. The freely available Vmatch, LTRharvest, Wise2, and MAFFT algorithms are required.