The purpose of this study was to evaluate technical performance, heart rate (HR), and activity profile in 7v7 and 8v8 soccer games for 9[FIGURE DASH]10-year-old girls (U11). A total of 24 female youth players participated in the study, all playing 20-min 7v7 and 8v8 games with 160 and 223 m per player, respectively. Technical actions, HR, and activity profile were measured during the games using video filming, HR monitors, and 5-Hz GPS units. The number of technical actions was higher in 7v7 than in 8v8 games (34±19 (±SD) vs. 28±14, p=0.03, d=0.37), as was the number of successful actions (25±16 vs. 20±12, p=0.01, d=0.35), with no difference in success rate for technical actions (70±13 vs. 69±14%, p=0.63, d=0.07). No differences were found between 7v7 and 8v8 in total distance covered (1574±251 and 1622±281 m, p=0.66, d=0.18), peak speed (19.5±2.6 and 20.7±1.5 km[BULLET OPERATOR]h, p=0.16, d=0.56), mean HR values (85±5 and 86±6%HRpeak, p=0.85, d=0.18), and time >90%HRpeak (37±16 and 34±16% of playing time, p=0.76, d=0.13). Distance covered at the highest running speeds of >16 km[BULLET OPERATOR]h was lower in 7v7 than in 8v8 games (34±24 vs. 63±34 m, p=0.018, d=0.98), as was number of entries into this speed zone (8±5 vs. 13±7, p=0.006, d=0.82). In conclusion, more technical actions and successful actions were observed in 7v7 than in 8v8 games, but players covered more ground with high-speed running in 8v8. This study also revealed that HR values were high in both game formats for U11 adolescent female players, with no difference between formats.