PseudoBase++2.0 is the updated version of Pseudobase++ (Taufer et al. 2009), which offered a searchable database of then confirmed pseudoknots in Pseudobase presented with a user-friendly interface for researchers to search, visualize, and analyze the data. With PseudoBase++ 2.0, the scientists can now visualize selected structures with PseudoViewer, map existing sequences to NCBI, and insert new pseudoknots to the PseudoBase dataset through a syntax-controlled interface that prevents structural errors for long sequences. PseudoBase++2.0 is part of the RNAVLab project for computational analyses of RNA sequences, structures, and functions and serves the specific purpose of facilitating the prediction and analysis of pseudoknots.