Waveguide-fed slot radiators are widely used in several strategic applications. The published literature in this area is vast, spanning a period of nearly 50 years. There is a need for consolidating the information and present it at a glance, to aid future research. The purpose of this article is to present a survey of the published literature in the area of waveguide-fed slot radiators. Specifically, the topics covered include longitudinal / transverse broadwall radiating slots, dielectric filled/ covered slots, compound/centred-inclined radiating slots, narrow wall slots, ridged waveguide slots, etc. This survey does not include the literature on the array design, as it would have resulted in limiting the information on the slot radiators. Besides, it is felt that the slot array analysis and design techniques would merit a survey of their own.