Yarns of 37 different sizes ranging from 0.08 to 3.0 mm diameter were found to be in use for fishing purposes, in South India. The physical and mechanical properties viz., linear density, runnage and the tensile break-load and elongation of nylon monofilament yarns were assessed. Of the 37 diameters tested, BIS (Bureau of Indian Standards) standards are available only for 17. Out of the 17 diameters of yarns tested, only 12 conformed to the standards with reference to runnage, 4 for break-load and all for elongation. Properties of yarns of 24 sizes in the range of 0.08 to 1.0 mm suitable for fabrication of gillnets are presented in this paper. The relationship between wet knot break-load and R-tex was found more significant than wet knot break-load and diameter. Samples of 0.16 and 0.20 mm diameter lost 55% of their original break-load at the end of 300 days exposure to sunlight while 0.23 mm lost 49 % and 0.32 mm diameter yarns lost 31% of original break-load. The standard specifications required for yarns of each diameter were worked out for the materials suitable for fabrication of gillnet which would help in selection of the yarns for a specific fishery

Polyamide monofilament yarn, gillnet, break-load, elongation