Mufasa had a loving relationship with his son. Simba spent much of his time with his father, who taught him how to be a good king. When Mufasa was killed in the stampede, Simba was heartbroken, believing that it was his own fault. When Mufasa appeared again to Simba years later as a spirit, he encouraged him to return to the Pride Lands, telling him to remember who he is: Mufasa's son, the one true king. Even in death, Simba looks to his father for guidance.
Mufasa and his mate, Sarabi, loved each other very much. When Mufasa was killed in the wildebeest stampede, she was heartbroken.
Mufasa did not have a very good relationship with his brother. While Mufasa did love Scar, he wasn't sure of what to do about his bad attitude. Scar was frequently disrespectful towards Mufasa, which sometimes caused the latter to lose his patience with his brother. Mufasa failed to see Scar's treachery until it was too late, when Scar murdered him.
Although Mufasa never interacted with his grandson during his lifetime, Kion still held a great deal of respect towards Mufasa. Whenever he was in doubt, Kion almost always called upon the spirit of his grandfather for guidance.
Mufasa had a very good friendship with his majordomo. He often turned to Zazu for advice, and tasks him with reporting the kingdom's affairs to him. The duo often cracked jokes with each other, usually at Scar's expense. However, Mufasa wasn't above teasing Zazu, as seen when he uses him as the target for Simba's pouncing lesson.
Mufasa had a very close friendship with Rafiki.
The hyenas were Mufasa's greatest enemies. They would often trespass into the pride lands, and Mufasa had to drive them out. When the trio tried to attack Simba, Mufasa viciously fought back, and threatened them should they try again.