We assess bias in the record of kimberlite volcanism by using newly acquired size data on more than 900 kimberlite bodies from 12 kimberlite fi elds eroded to depths of between 0 m and >1200 m, and by a comparison with intraplate monogenetic basaltic volcanic fi elds. Eroded kimberlite fi elds are composed of pipes (or diatremes) and dikes, and within any one kimberlite fi eld, regardless of erosion level, kimberlite bodies vary in area at Earth's surface over 2-3 orders of magnitude. Typically 60%-70% of the bodies are <10% the area of the largest pipe in the fi eld. The maximum size of a kimberlite pipe found in a fi eld shows a relationship with estimated erosion levels, suggesting that the erosion level of a region could be used to predict the maximum potential size of a pipe where it intersects the surface. The data indicate that the selective removal of surface volcanic structures and deposits by erosion has distorted the geological record of kimberlite volcanism. Selective mining of preferentially large, diamondiferous kimberlite pipes and underreporting of small kimberlite pipes and dikes add further bias. A comparison of kimberlite volcanic fi elds with intraplate monogenetic basaltic volcanic fi elds indicates that both types of volcanism overlap in terms of fi eld size, volcano number and size, and typical erupted volumes. Eroded monogenetic basaltic fi elds consist of dikes that fed effusive and weakly explosive surface eruptions, and diatremes (pipes) generated during phreatomagmatic eruptions, and they are structurally similar to eroded kimberlite fi elds. Reassessment of published data suggests that kimberlite magmas can erupt in a variety of ways and that most published data, taken from the largest kimberlite pipes, may not be representative of kimberlite volcanism as a whole. This refuels long-standing debates as to whether kimberlite pipes (diatremes) primarily result from phreatomagmatic eruptions (as in basaltic volcanism) or from volatile-driven magmatic eruptions.