Dash worked for 20 years as contributing editor and publisher of the journal Fortean Times, which specialises in the study and research of strange and anomalous phenomena. He is regarded as one of the most serious modern investigators into such phenomena, preferring the use of first hand sources and other historically accurate information. His works investigate misconceptions and errors in the field of strange phenomena, typically finding a middle path between "believers" (who, in Dash's view, often accept extraordinary or unusual claims without investigation or on scant evidence) and skeptics and debunkers (who, in Dash's view, often overlook interesting or valuable evidence in their seeming desire to disprove alleged paranormal or anomalous phenomena). In Borderlands (1997), Dash repeatedly notes that researchers of unusual phenomena must always be wary of potential hoaxes; time and again people have perpetrated elaborate pranks or hoaxes with little motive other than to fool others.
Dash has published six books, and a number of articles and papers in Fortean Times and later spin-off titles such as the academic annual Fortean Studies, published from 1994 through 2000.