Should I watch FMA before FMAB?

When It Makes Sense

• Good fit: You enjoy exploring how a story can evolve when adapted multiple times and have the time to invest in two separate series. Watching the 2003 Fullmetal Alchemist first lets you experience the original creator’s early vision and the emotional twists that differ from the manga.
• Good fit: You are a completist collector who wants to discuss every nuance with fellow fans, including the distinct character arcs and filler episodes that only appear in the 2003 version.

When You Should Avoid It

• Warning sign: Your schedule is limited and you prefer a single, tightly‑paced narrative. Brotherhood condenses the story into a 64‑episode run that follows the manga closely, so watching both may feel redundant.
• Warning sign: You are new to anime and risk confusion from the divergent endings and character developments between the two series.

Pros and Cons

Pros

• Provides two complementary perspectives: the 2003 series offers original plot twists, while Brotherhood delivers the canonical ending.
• Enhances appreciation of thematic depth, such as sacrifice and the consequences of hubris, by seeing how each adaptation handles them.

Cons

• Requires a significant time commitment—approximately 100 episodes total—potentially leading to viewer fatigue.
• Repeats major plot points, which may diminish the emotional impact when the story is retold in Brotherhood.

Decision Checklist

• Do I have at least 30 hours of free viewing time to watch both series without rushing?
• Am I comfortable revisiting the same story beats with different outcomes?
• Will watching the 2003 version enhance my enjoyment of Brotherhood, or will it create unnecessary spoilers/confusion?

Alternatives to Consider

If time or narrative focus is a concern, you can start directly with Fullmetal Alchemist: Brotherhood, which follows the manga’s storyline from start to finish. Another option is to watch the 2003 series first and then skip the episodes that heavily overlap with Brotherhood, using episode guides to identify filler or duplicated arcs.

Final Recommendation

For viewers who appreciate deep dives into alternate storytelling and have the schedule to accommodate it, watching Fullmetal Alchemist before Fullmetal Alchemist: Brotherhood can enrich the overall experience. If you prefer a streamlined, manga‑faithful journey or have limited viewing time, starting with Brotherhood is the more efficient path. As with any entertainment decision, weigh your personal preferences, time constraints, and desire for narrative variety before committing.