The practice of the Karma yoga system can be combined with the practice of other forms of yoga, especially Bhakti Yoga, Hatha Yoga, Raja yoga, Laya Yoga. This is one of the main themes of Kåñna‘s teachings exposed in Bhagavad Gita. On this subject I will give several quotes:
"Abandon and offer all your works to the Divine." "No matter what you do, do it detachedly as an offering to me. This way you will be free of the good or bad results which are making chains of the selfish action." "Do all your actions detached, driven only by your love for me." "The one who is at the root of all beings and who permeates the entire Universe - only by adoring Him through activity done with detachment, can a person easily obtain perfection".
For Sri Aurobindo, Karma Yoga is most efficient when "we abandon our own will and our selfish desires to the Divine will". (Practical Integral Yoga)
Sri Ramakrishna was telling those who came to consult him: "pray to God to send you His grace and the strength to accomplish your duties with detachment, without hoping for any inner or outer gratification and without fear of a punishment in this world or another". (Teachings of Ramakrishna).
Significantly, Kåñna insists upon the important role of spiritual knowledge and intelligence (in other words Jïana-Yoga) in the practice of Karma Yoga: "This is the intelligence about which you heard in Samkhya; listen now to what Yoga is teaching you: if you are in the state of Yoga through this intelligence, O Son of Pritha, you will eliminate forever the slavery of action". He goes on to say that Karma Yoga completes very well any other type of Yoga, among which are Raja Yoga, Tantra Yoga, Haöha Yoga, Laya Yoga, Bhakti Yoga.
For Sri Aurobindo "the activity done in a completely detached state of mind, as a form of spiritual training is a strong way in any form of Yoga".
Swami Ramadas states: "Without Karma Yoga the practice of Jïana-Yoga and Bhakti Yoga, Haöha Yoga, Tantra Yoga and Laya Yoga is only an extreme spiritual selfish glorification" (Letters).