Many bacterial small RNAs (sRNAs) regulate gene expression through base pairing with mRNAs, and it has been assumed that these sRNAs act solely by this one mechanism.  We discovered that the multi-cellular adhesive (McaS) sRNA of Escherichia coli uniquely acts by two different mechanisms:  base pairing and protein titration.  Previous work established that McaS base pairs with the mRNAs encoding master regulators of curli and flagella synthesis, respectively resulting in down- and up-regulation of these important cell surface structures.  We now found that McaS activates synthesis of the exopolysaccharide β-1,6 N-acetyl-D-glucosamine (PGA) by binding the global RNA binding protein CsrA, a negative regulator of pgaS translation.  The McaS RNA bears at least two CsrA binding sequences and inactivation of these sites compromises CsrA binding, PGA regulation and biofilm formation.  Moreover, ectopic McaS expression leads to induction of two additional CsrA repressed genes encoding diguanylate cyclases.  Collectively, our study shows that McaS is a dual function sRNAs with roles in the two major post-transcriptional regulons controlled by the RNA binding proteins Hfq and CsrA.