This study aimed to identify the difficulties of science teachers in planning and implementing out the assessment. The research design was simple descriptive design. The samples of this research were 30 science teacher at Kemiling sub-district of Bandar Lampung that were selected by using non-probability sampling technique. Data of the teacher difficulties in planning and implementing the assessment were obtained from questionnaires and interviews then analyzed descriptively. The result of the research showed that the average of teachers difficulties in planning the assessment was low (34.06%) and teachers difficulties in implementing out the assessment was low (29.73%). The highest difficulty in planning the assessment was on indicators setting up the assessment grid. While the highest difficulty in implementing the assessment was the psychomotor domain in observing the aspects assessed.Penelitian ini bertujuan untuk mengidentifikasi kesulitan guru IPA dalam merencanakan dan melaksanakan asesmen. Desain yang digunakan pada penelitian ini adalah desain deskriptif sederhana. Sampel penelitian adalah guru IPA SMP se-Kecamatan Kemiling Bandar Lampung berjumlah 30 guru yang dipilih dengan menggunakan teknik sampling non-probability. Data kesulitan guru dalam merencanakan dan melaksanakan asesmen diperoleh dari angket dan wawancara kemudian dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa rata-rata kesulitan guru dalam merencanakan asesmen tergolong rendah (34,06%) dan kesulitan guru dalam melaksanakan asesmen juga tergolong rendah (29,73%). Kesulitan tertinggi dalam merencanakan asesmen yaitu pada indikator menyusun kisi-kisi asesmen. Sementara kesulitan tertinggi dalam melaksanakan asesmen yaitu pada ranah psikomotorik dalam mengamati aspek yang dinilai.Kata kunci: asesmen, guru IPA, kesulitan, melaksanakan, merencanakan