<jats:title>Abstract</jats:title><jats:p>Two new pyrrolosesquiterpenes, <jats:bold>1</jats:bold> and <jats:bold>2</jats:bold>, were isolated from cultures of the soil actinomycete <jats:italic>Streptomyces</jats:italic> sp. Hd7–21. The structures of these compounds were established as (2<jats:italic>Z</jats:italic>,4<jats:italic>E</jats:italic>,9<jats:italic>E</jats:italic>)‐6,7,11‐trihydroxy‐3,7,11‐trimethyl‐1‐(1<jats:italic>H</jats:italic>‐pyrrol‐2‐yl)dodeca‐2,4,9‐trien‐1‐one (<jats:bold>1</jats:bold>) and (2<jats:italic>Z</jats:italic>,4<jats:italic>E</jats:italic>)‐5‐{3‐[(2<jats:italic>E</jats:italic>)‐4‐hydroxy‐4‐methylpent‐2‐en‐1‐yl]‐3‐methyloxiran‐2‐yl}‐3‐methyl‐1‐(1<jats:italic>H</jats:italic>‐pyrrol‐2‐yl)penta‐2,4‐dien‐1‐one (<jats:bold>2</jats:bold>) by extensive spectroscopic analyses including MS, and 1D‐ and 2D‐NMR data. Their cytotoxic activities against a panel of human cancer cell lines were evaluated.