Gill-cleaning mechanisms of the burrowing mud shrimp Laomedia astacina De Haan, 1849, were examined based on morphology and behavioral observations. The gill complement consists of 13 arthrobranchs and 5 podobranchs, with flattened gill filaments of the phylloid trichobranch type. Gill cleaning is based on passive mechanisms involving setal systems on the scaphognathite, epipods, setobranch, and pereiopodal coxae. Multidenticulate scaphognathite setae (MSS) bearing digitate scale setules project into the gill chamber, lying over gill filaments. Proximal setules of the MSS incline to the setal base while distal setules incline to the tip; the transition zone of setule inclination is marked with an annulus. Setiferous epipods on the limb bases, except on fifth pereiopods, are armed with serrate setae, which contact adjacent gill filaments and coxal surfaces. Multidenticulate setobranch setae are found only on the coxae of third maxillipeds, thus limiting their gill cleaning functions to the anterior gills. Pereiopodal coxae bear tufts of short serrate setae together with a few multiple double-prong setae that are morphologically atypical in decapods. Active gill cleaning by pereiopodal brushes, as in callianassids and upogebiids, and limb rocking, as in astacideans, were not observed. Among thalassinideans, gill-cleaning mechanisms of laomediids appear more closely allied to those of thalassinids than callianassids and upogebiids, whereas those of axioids possibly indicate an ancestral condition.