Small RNAs (smRNAs), which include microRNAs (miRNAs), small-interfering RNAS (siRNAs) and trans-acting siRNAs (ta-siRNAs) are ~19-24 nt RNAs that are important negative regulators of nucleotide sequences involved in development, homeostasis and in the maintenance of heterochromatic states. The Cereals Small RNA Database (CSRDB) is an integrated resource for small RNAs expressed in rice and maize that includes a genome browser and a smRNA-target relational database as well as relevant bioinformatic tools. The resource currently contains a preliminary dataset of 35,454 and 68,871 mapped smRNA sequence reads for rice and maize respectively. Future updates will include smRNA data derived from different tissues and conditions. The database is accessible online at http://sundarlab.ucdavis.edu/smrnas/.