The first recorded appearance in the Southern California Bight (SCB) of ten decapod crustaceans, all of which have distributions that are primarily tropical or sub-tropical, is documented. Northern range extensions are provided for the penaeidean shrimp Metapenaeopsis mineri (Penaeidae) and Sicyonia penicillata (Sicyoniidae), the caridean shrimp Processa peruviana (Processidae), Pantomus qffinis, Plesionika beebei, P. trispinus, and P. carinirostris (Pandalidae) and the brachyuran crabs Stenorhynchus debilis (Majidae), Palicus cortezi, and P. lucasii (Palicidae). These animals were collected during or in the aftermath of the 1991/92 and 1997/98 El Nino events. The specimens were collected in trawl monitoring programs of shelf and upper slope depths that have been in place for up to three decades. These long term data sets provide evidence of previous absence from the SCB, accentuating the novelty of these records.