"The free-trade agreement with the United States will cause the downfall of this industry, the pride of our economy," Muhammad Rhauti, president of the Council of the Order of Moroccan Pharmacists, said on Wednesday.
The Moroccan pharmaceutical industry employs 30,000 people, supplies 80% of the country's requirements and exports 10% of its production, he told Aujourd'hui Le Maroc newspaper.
"Citizens will be the first to suffer because access to far cheaper generic medicines will be delayed," he said, saying that imported US medicines would retail at high prices.
"If we increase prices, most people will never have access to medicines," he warned, saying that Moroccans spend $450 million per year on medicines, an average of $17 (170 dirhams) per person.
The Moroccan association for the fight against HIV/AIDS has also voiced concerns.
The agreement, under which Rabat agreed to impose high penalties for intellectual property and trademark violations, could undermine access to cheap medicines.
The US-Moroccan agreement, which is due to be ratified by the Rabat parliament next week, calls for the elimination of customs tariffs on 95% of industrial and commercial goods.
It covers industrial and agricultural goods, intellectual property, services, customs, employment, the environment and telecommunications.
The North African nation is the United States' 73rd largest trade partner.