Sno/scaRNA database (sno/scaRNAbase, http://bioinfo.fudan.edu.cn/snoRNAbase.nsf) was developed to facilitate the research of small nucleolar RNAs (snoRNAs) and cajal body-specific RNAs (scaRNAs) that have been found to play important roles in rRNA, tRNA, snRNA and even mRNA biogenesis. Derived from a systematic literature curation and annotation effort, the sno/scaRNAbase currently contains 1,979 sno/scaRNAs records obtained from 85 organisms. It provides an easy-to-use gateway to important sno/scaRNAs features such as conserved sequence motifs and antisense elements of sno/scaRNA families, methylation or pseudouridylationsites that a sno/scaRNA guides, homologues, predicted secondary structures, genomics organizations, sno/scaRNA genes, chromosome locations, functions that are experimentally verified or predicted, etc. Approximate searches, in addition to accurate and straightforward searches, make the database search more flexible. A BLAST search engine is implemented to enable blast of query sequences against all sno/scaRNAbase sequences. This sno/scaRNAbase serves as a more uniform and friendly platform for sno/scaRNA research.