ABSTRAK Di beberapa pelayanan kesehatan masih ditemukan ibu-ibu yang kurang memiliki pengetahuan tentang kebutuhan gizi pada masa nifas. Ibu-ibu kadang menunjukkan perilaku negatif seperti pantangan minum susu dan makan ikan, sehingga kepercayaan ibu nifas pantang mengonsumsi makanan tertentu menyebabkan kondisi ibu kekurangan zat gizi yang berkualitas. Tujuan penelitian adalah untuk mengetahui gambaran perilaku diet ibu nifas di Desa Tanjung Sari Kecamatan Batang Kuis Kabupaten Deli Serdang. Penelitian ini bersifat deskriptif. Populasi adalah seluruh ibu nifas yang berjumlah 30 orang dengan jumlah sampel adalah total sampling. Pengumpulan data dengan menggunakan kuesioner yang terdiri dari karakteristik ibu nifas, pengetahuan, sikap dan tindakan ibu nifas. Jumlah konsumsi energi dan protein diperoleh melalui survei konsumsi makanan dengan metoda Food Recall 24 jam. Data yang sudah dikumpulkan dianalisa secara deskriptif. Hasil penelitian menunjukkan bahwa hanya 13,33% ibu nifas memiliki pengetahuan baik, bahkan ditemukan 3,33% tingkat pengetahuan kurang. Demikian juga dalam hal sikap dan tindakan ibu nifas, hanya 26,67% dan 16,67% ibu nifas memiliki sikap dan tindakan baik, sementara kategori kurang hanya ditemukan pada tindakan ibu nifas yaitu 3,33%. Dalam hal konsumsi energi ibu nifas yang paling banyak pada kategori baik (63,33%), dan yang paling sedikit berada pada kategori kurang (3,33%), sementara tingkat konsumsi protein paling banyak pada kategori kurang (43,33%) dan defisit (36,67%). Disarankan kepada petugas gizi puskesmas agar melakukan pendekatan kepada bidan desa untuk melakukan penyuluhan gizi kepada ibu hamil dan ibu menyusui. Kata kunci : pengetahuan, sikap, tindakan, diet ibu nifas Universitas Sumatera Utara ABSTRACT In some health services there are several mothers with the lack of knowing knowledge about dietary of the post-partum mothers. The mothers sometime show negative behaviors such as taboo for drinking milk and eating fishes so that their belief of taboo of eating some certain foods lead to their condition with lack of quality nutrition. The objective of the study is to know the description of the dietary behaviors of the post partum mothers at Tanjung Sari Village of Batang Kuis of Deli Serdang Regency. The study is a descriptive one. The population included 30 post partum mothers in which the samples were taken by total sampling method. The data collection was conducted by using questionnaire consisting of the characteristics of the post partum mothers, their knowledge, attitude and action. The total consumed energy and protein was found by consumption survey of the food by using 24-hours Food Recall method. The collected data were then analyzed descriptively. The result of the study showed that there were only 13.33% of the post partum mothers who adequate categorized knowledge, and even there were 3.33% of those with inadequate knowledge. Similarly, in the case of attitude and action of the post partum mothers, there were only 26.67% and 16.67% of the post partum mothers who have adequate attitude and action, whereas the inadequate categorized knowledge was found in the case of their action (3.33%). In the case of the consumed energy, majority of them belonged to those with adequate knowledge (63.33%) and the most least belonged to inadequate category ( 3.33%). Whereas majority of the protein consumption belonged to inadequate (43.33%) and deficit (36,67%). It is suggested that the nutritional providers of the primary health center (Puskesmas) to midwive to increase guidance to pregnant mothers and lactating mothers. Keywords : knowledge, attitude, action, dietary of the post-partum mothers Universitas Sumatera Utara