Most researchers of Arabic sociolinguistics assume the existence of a sociolinguistic continuum with a local vernacular at the bottom and the standard variety at the top. Those researchers seem to equate the terms “prestige” and “standard”; consequently, they tend to consider Modern Standard Arabic (MSA) as the only prestige variety in all settings. This article presents evidence showing that if an adequate description of sociolinguistic variation of spoken Arabic is to be met, it is necessary to posit not only one standard speech variety, MSA, but also other prestigious local or regional varieties which act as local spoken standards competing with MSA in informal settings. It will be shown in the reported cases that in certain contexts speakers tend to switch from their local forms – though these latter may be identical to MSA – to other local features characteristic of other dominant social groups and that happen to be marked [–MSA], These local prestigious norms act like the standard spoken norms in informal settings. (Diglossic model, prestigious varieties, stereotypes, dominant social groups, competing standards, spoken Arabic).