Image captioning is a multidisciplinary artificial intelligence (AI) research task that has captures the interest of both image and natural language processing experts. Image captioning is a complex problem as it sometimes requires accessing the information that may not be directly visualized in a given scene. It possibly will require common sense interpretation or the detailed knowledge about the object present in image. In this paper, we have given a method that utilizes both visual and external knowledge from knowledge bases such as ConceptNet for better description the images. We demonstrated the usefulness of the method on two publicly available datasets; Flickr8k and Flickr30k.The results explain that the proposed model outperforms the state-of-the art approaches for generating image captions. At last, we will talk about possible future prospects in image captioning.