Forty-nine Manchega breed suckling lambs were used. Carcass weight was less than 13 kg, and lambs were slaughtered at 10, 12 and 14 kg liveweight. Carcasses were classified by three assessors on colour photographs, by several classification methods: the European Union scale for light lambs carcasses (EU), Colomer-Rocher methods for fatness (CF) and conformation (CC), and the new scale for suckling lambs (SL) developed by our research group. Carcasses were also assessed using these scales divided into 0.25 point-intervals (EU-25, CF-25, CC-25 and SL-25). A correlation analysis was made between assessors score and tissue composition in the carcass and in three joints (leg, best end of neck and loin, and shoulder). For all the methods studied 0.25 point scales were best correlated to tissue composition than 1.0 points-interval scales. When 1.0 point-interval scales were used the SL scale was best correlated to tissue composition. When 0.25 point-scales were used, the EU scale gave the best correlations. Conformation scale (CC) was useful to predict carcass composition, specially kidney knob and channel fat content.