This work investigated the effects of different protein supplements (fetal calf serum (FCS) and bovine serum albumin (BSA)) on the in vitro development of caprine preantral follicles. Preantral follicles (≥ 150 µm) were isolated from ovarian cortex fragments and individually cultivated in α-MEM medium in an incubator at 37°C for 24 days with 5% atmospheric CO2, and supplemented with either BSA at 1.25 or 3.0 mg/ml or FCS at 5 or 10%. An evaluation of follicular development was conducted based on survival rate, antrum formation, increase in follicular diameter, oocyte viability and obtainment of fully-grown oocytes. It was observed that from the 12th cultivation day, the percentage of surviving follicles under treatment with BSA at 3.0 mg/ml was greater than that of the other treatments (P < 0.05). As for follicular growth, although on the 6th day of cultivation FCS-treated follicles had a greater mean diameter (P < 0.05) when compared to those treated with BSA, on the last day of cultivation the mean diameter and antrum formation of follicles treated with BSA at 3.0 mg/ml were greater than those of follicles under other treatments (P < 0.05). With oocyte growth, the percentage of oocytes cultivated with BSA (3.0 mg/ml) that were destined for in vitro maturation (IVM; ≥110 μm diameter) was higher than that of other treatments. Moreover, under this treatment, 86% of oocytes presented a germinal vesicle and 14% restarted meiosis, out of which 3% were mature (metaphase II). In conclusion, supplementing cultivation medium with BSA at 3.0 mg/ml not only improves follicular development but also provides meioticallycompetent oocytes after in vitro cultivation of caprine preantral isolated follicles.