Yoruba Ecotype Chicken (YEC) is characterized by hardiness, and better adaptation to prevailing tropical environment. However, its small body size and egg weight has hindered its utilization for commercial meat and egg production. Crossbreeding is a major tool used in improving desired traits in animals. The objectives of the study were to: (i) evaluate fertility, hatchability, growth performance and survivability in Marshall (MM), Goliath (GG), Sussex (SS) and their crossbred with YEC; (ii) evaluate egg production and quality characteristics in YEC and its crosses with GG and SS; and (iii) estimate genetic parameters, predictive models for growth and egg production traits in YEC and its crosses.rnTwo experiments were conducted. Experiment 1 examined fertility, hatchability, early and late growth performance and survivability using a total of 529 chicks obtained from 971 eggs `that were collected from purebred chickens and their crosses (MMxMM, GGxGG, SSxSS, YECxYEC, YECxMM, YECxGG, YECxSS, MMxYEC, GGxYEC and SSxYEC). Experiment 2 investigated egg production and egg quality characteristics using 120 sixteen-week old YEC and its crosses. Data obtained from experiments 1 and 2 estimated heterosis, heritability, repeatability, correlation, predictive equations, principal component and genetic relatedness for body weight and egg parameters. Data on growth and reproductive parameters were subjected to analysis of variance. rnThe findings of the study were that:rni. MMxYEC had the highest fertility (97.50%) compared to other crosses. Hatchability was highest in MMxYEC and GGxYEC (89.74% in both);rnii. MMxMM and MMxYEC had significantly (p<0.05) higher feed intake, weight gain and feed conversion ratio than other crosses. YECxYEC had 91.20% survivability. Survivability was highest in YECxGG (100%) at early and late growth phases;rniii. egg parameters were significantly higher (p<0.05) and maturity occurred earlier (154 days) in YECxSS than in YECxYEC (146 days) and other YEC crosses. Crosses between YEC cock and exotic hens exhibited positive heterosis for body weight and egg parameters;rniv. heritability for body weight was higher in YECxGG (0.38 to 0.63) and GGxYEC (0.59 to 1.00) than in YECxYEC. Repeatability estimates were generally low in YECxYEC and its crosses;rnv. body weight was best predicted by cubic and quadratic equations in most crosses, Principal component 1 accounted for the highest variance in weekly body weight with the low variation existing in SSxSS, YECxGG, YECxMM and MMxYEC. Crosses of SSxSS, YECxGG and YECxSS were best described by egg external quality traits while GGxGG, GGxYEC and SSxYEC were described by external and internal quality traits ; andrnvi. Dendogram showed that body weight of YECxYEC was more closely related with SSxSS and GGxGG than MMxMM. Similarity existed between egg number of YECxYEC and GGxGG while the egg weight of the two strains were far apart in the dendogram.rnrnThe study concluded that cross breeding improved body weight and egg production of YEC. Crossbred YECxMM or YECxGG is therefore recommended for body weight and YEC x SS for egg production in Nigeria.