In the wake of the news that Iran—one of the greatest untapped markets—is finally opening up, investment strategists and fund managers are clamoring to be at the forefront of the emerging market that the Islamic Republic represents. The more adventurous among them have already booked their flights to Tehran.

There is no doubt the Iranian market holds enormous potential.  However, the first word of advice for anyone looking to enter the Iranian market: proceed with caution.

The statistics are tempting: Iran has a population close to 80 million with high literacy rates and a sizable middle class. Sixty percent are under the age of 35, most of whom are attracted to almost any Western product, and the country holds an abundance of natural resources.

While attending the first major EU-Iran trade conference in Vienna last month, I witnessed both Iran’s openness to investors and also the great interest participants had towards Iran’s market. The 400 participants eagerly listened to all the guest speakers and panels as high level officials from Iran proudly announced that the Islamic Republic was now open for business.

Foreign nationals need to be attuned to the business culture in Iran. If one doesn’t have the proper strategy to navigate this culture, months and years can be wasted.

You need at least one reliable local partner, someone who will look out for your best interests, who knows the local market, has very high-level contacts, and is not looking to make fees on the side.  Finding such partners could be the most important strategic move you make.  Almost everyone you speak to Iran will claim they have the resources and contacts you are seeking, but in reality very few do.

Patience could be the number one virtue you need when dealing with any Iranian counterpart.  When you walk out of that Monday morning meeting and shake hands with the parties in Iran and they say they’ll have the agreement signed by Wednesday, you need to ask, “Which Wednesday?”  Time and deadlines that we’ve come to expect in North America and Europe take on a new meaning in Iran.

“Inshallah” which translates to “God willing” is a common phrase you may hear while in Iran.  If your counterpart replies “inshallah” to a question about whether we are ready to move forward, that means that we have just started and still have many details to sort out.

Iran has been largely closed for international investment for past 35-years and it is not the market for everyone. Yet, if prepared, with patience, resources and the right team, Iran can be the investment opportunity of a lifetime.

Europeans and Asians are leading the surge towards investment in Iran. American companies can follow but they need to do two things. First, they must check with the U.S Treasury Department about whether an OFAC license or special waiver is required. Second, they must proceed with caution and to do their homework in advance. If they heed these words the rewards can be many and the inevitable frustrations will be worth it in the end.

Namjoo Hashemi is managing director of Pangea, LLC based in Los Angeles, California, a firm that provides advisory and consulting services to international clients.