Combination of matrix isolation techniques with theoretical methods for identification and characterization of some dithiiranes and oxathiiranes is presented. In general, both dithiiranes and oxathiiranes were generated via flask vacuum pyrolysis of suitable sulfur-containing precursors such as 1,2,4-trithiolanes, 1,3-dithietane 1,3-dioxide or thiocarbonyl S-oxides (sulfines). Novel applications of dimethyldioxirane (DMDO) and (trifluoromethyl)methyl dioxirane (TFMDO) as versatile oxidizing reagents published in the period 2008–2018 are summarized. Methods applied for manufacturing of new polymeric materials functionalized with dioxirane moieties and reported in patents are presented. Mechanisms involving Criegee intermediates in reactions of carbonyl compounds with dioxiranes using experimental and theoretical methods are discussed in the light of recent results.