Its main accomplishments were settlement of the Christological issue of the divine nature of God the Son and his relationship to God the Father, the construction of the first part of the Nicene Creed, establishing uniform observance of the date of Easter, and promulgation of early canon law.
Pencapaian utamanya adalah penyelesaian isu Kristologis mengenai kodrat Putra Allah dan hubungannya dengan Allah Bapa, pembentukan bagian pertama Pengakuan Iman Nicea, menetapkan keseragaman waktu perayaan Paskah, dan pengundangan hukum kanon awal.