This paper deal with the length-weight relationship and the condition factor of Macrodon ancylodon caught by trawls along the southern coast of Brazil (29ºS to 32ºS], from September/1976 to August/1977. The total length (cm) was correlated with the weight (g), by means of the expression W = aLb, adjusted by least square method, after a logarithmic transformation. We can observe three periods concerned length-weight relationship: (1) October, November, December and January, with highest weights values; (2) February, March, April and May, with smallest weights values; and (3) June, July, August and September, with intermediary weights between the other periods. We did'nt observe considerable differences between males and females. The condition factor increase with the length increment. The highest condition factor values were observed in November and the smallest in April.