The most important item you’ll have is your backpack, as it is the determining factor in how much you take into the jungle. Besides its size, think about its comfort level, especially for your back and shoulders. Also make sure your backpack is extremely durable, sturdy and waterproof because it will have to endure quite a bit on this trip. Rolling suitcases and duffel bags are generally not as useful as backpacks because they are too much work to carry. Putting the bulk of the heavy weight on your back makes it easier to walk. Also consider taking along a smaller daypack for on-hand items.
The weather of the Amazon is hot and wet, but, depending on the time of year, the evenings can get quite chilly. Dressing accordingly in the jungle also has to do with your own personal preferences. Generally, loose cotton long-sleeved shirts and T-shirts are best. Quick drying pants and shorts are also suitable. Because of the wetness, consider bringing a poncho as well. An all-purpose sweater is useful for cooler nights. A sun or rain hat or cap can come in handy.
For most of your days spent in the Amazon rainforest, you will be on your feet walking, wading, or hiking. Comfort and protection of your feet are important. A pair of strong hiking boots is key, especially ones that reach your ankles to prevent possible snake bites. In addition to your hiking boots, bring some normal walking shoes. Also a pair of cheap, rubber sandals is particularly practical if you cross small streams or go swimming, protecting your feet on uneven ground.
Depending on your style of travel, who you’re traveling with and your physical endurance, you’ll have to tweak your own lists. However, the following are common items that most experienced Amazon travelers take along: mosquito repellent, sunblock, anti-itch cream, a pocketknife, a first-aid kit, a flashlight with extra batters and a water flask. Other items to consider include: waterproof matches, string, duct tape, and zip-close bags. A heavy-duty, waterproof bag for items such as cameras, phones, wallets and passports is also practical. When in doubt, ask yourself whether any item you're considering including is worth the extra weight on your back.